[Bug] `CONVERT_TO` RP2040 targets broken with `UART_DRIVER_REQUIRED=yes`

Describe the Bug

I'm fixing up the Bit-C PRO RP2040 converters and have run into an issue with UART_DRIVER_REQUIRED, which has been introduced in the latest breaking change merge. All extra source included in rules.mk fail to compile with the following error:

Compiling: keyboards/nullbitsco/nibble/matrix.c                                                    In file included from ./lib/chibios/os/hal/include/hal.h:319,
                 from platforms/chibios/platform_deps.h:18,
                 from quantum/quantum.h:18,
                 from keyboards/nullbitsco/nibble/matrix.c:16:
./lib/chibios/os/hal/include/hal_serial.h:99:10: fatal error: hal_serial_lld.h: No such file or directory
   99 | #include "hal_serial_lld.h"
      |          ^~~~~~~~~~~~~~~~~~
compilation terminated.
 [ERRORS]

Keyboard Used

nullbitsco/nibble

Link to product page (if applicable)

No response

Operating System

Ubuntu 22.04

qmk doctor Output

Ψ QMK Doctor is checking your environment.
Ψ CLI version: 1.1.1
Ψ QMK home: /home/ubuntu/firmware/qmk_firmware
Ψ Detected Linux (Ubuntu 22.04.2 LTS).
⚠ Missing or outdated udev rules for 'atmel-dfu' boards. Run 'sudo cp /home/ubuntu/firmware/qmk_firmware/util/udev/50-qmk.rules /etc/udev/rules.d/'.
⚠ Missing or outdated udev rules for 'kiibohd' boards. Run 'sudo cp /home/ubuntu/firmware/qmk_firmware/util/udev/50-qmk.rules /etc/udev/rules.d/'.
⚠ Missing or outdated udev rules for 'stm32-dfu' boards. Run 'sudo cp /home/ubuntu/firmware/qmk_firmware/util/udev/50-qmk.rules /etc/udev/rules.d/'.
⚠ Missing or outdated udev rules for 'apm32-dfu' boards. Run 'sudo cp /home/ubuntu/firmware/qmk_firmware/util/udev/50-qmk.rules /etc/udev/rules.d/'.
⚠ Missing or outdated udev rules for 'gd32v-dfu' boards. Run 'sudo cp /home/ubuntu/firmware/qmk_firmware/util/udev/50-qmk.rules /etc/udev/rules.d/'.
⚠ Missing or outdated udev rules for 'wb32-dfu' boards. Run 'sudo cp /home/ubuntu/firmware/qmk_firmware/util/udev/50-qmk.rules /etc/udev/rules.d/'.
⚠ Missing or outdated udev rules for 'bootloadhid' boards. Run 'sudo cp /home/ubuntu/firmware/qmk_firmware/util/udev/50-qmk.rules /etc/udev/rules.d/'.
⚠ Missing or outdated udev rules for 'usbasploader' boards. Run 'sudo cp /home/ubuntu/firmware/qmk_firmware/util/udev/50-qmk.rules /etc/udev/rules.d/'.
⚠ Missing or outdated udev rules for 'usbtinyisp' boards. Run 'sudo cp /home/ubuntu/firmware/qmk_firmware/util/udev/50-qmk.rules /etc/udev/rules.d/'.
⚠ Missing or outdated udev rules for 'md-boot' boards. Run 'sudo cp /home/ubuntu/firmware/qmk_firmware/util/udev/50-qmk.rules /etc/udev/rules.d/'.
⚠ Detected ModemManager without the necessary udev rules. Please either disable it or set the appropriate udev rules if you are using a Pro Micro.
⚠ Missing or outdated udev rules for 'caterina' boards. Run 'sudo cp /home/ubuntu/firmware/qmk_firmware/util/udev/50-qmk.rules /etc/udev/rules.d/'.
⚠ Missing or outdated udev rules for 'hid-bootloader' boards. Run 'sudo cp /home/ubuntu/firmware/qmk_firmware/util/udev/50-qmk.rules /etc/udev/rules.d/'.
Ψ Userspace enabled: False
Ψ Git branch: master
Ψ Repo version: 0.23.1
⚠ Git has unstashed/uncommitted changes.
Ψ - Latest master: 2023-12-08 09:55:24 +0000 (0f341dfdd3) -- Fix TARGET when using converters (#22591)
Ψ - Latest upstream/master: 2023-12-08 09:55:24 +0000 (0f341dfdd3) -- Fix TARGET when using converters (#22591)
Ψ - Latest upstream/develop: 2023-12-08 15:57:34 +0000 (42245651e7) -- Align Dip Switch feature (#22625)
Ψ - Common ancestor with upstream/master: 2023-12-08 09:55:24 +0000 (0f341dfdd3) -- Fix TARGET when using converters (#22591)
Ψ - Common ancestor with upstream/develop: 2023-12-08 09:55:24 +0000 (0f341dfdd3) -- Fix TARGET when using converters (#22591)
Ψ CLI installed in virtualenv.
☒ Can't find avrdude in your path.
Would you like to install dependencies? [Y/n] m
Would you like to install dependencies? [Y/n] n
Ψ Found arm-none-eabi-gcc version 10.3.1
Ψ Found avr-gcc version 8.2.0
⚠ Unknown version for avrdude
Ψ Found dfu-programmer version 0.6.1
Ψ Found dfu-util version 0.9
Ψ Submodules are up to date.
Ψ Submodule status:
Ψ - lib/chibios: 2023-04-15 13:48:04 +0000 --  (11edb16109)
Ψ - lib/chibios-contrib: 2023-07-17 11:39:05 +0200 --  (da78eb37)
Ψ - lib/googletest: 2021-06-11 06:37:43 -0700 --  (e2239ee6)
Ψ - lib/lufa: 2022-08-26 12:09:55 +1000 --  (549b97320)
Ψ - lib/vusb: 2022-06-13 09:18:17 +1000 --  (819dbc1)
Ψ - lib/printf: 2022-06-29 23:59:58 +0300 --  (c2e3b4e)
Ψ - lib/pico-sdk: 2023-02-12 20:19:37 +0100 --  (a3398d8)
Ψ - lib/lvgl: 2022-04-11 04:44:53 -0600 --  (e19410f8)
Ψ Major problems detected, please fix these problems before proceeding.
Ψ Check out the FAQ (https://docs.qmk.fm/#/faq_build) or join the QMK Discord (https://discord.gg/Uq7gcHh) for help.

Is AutoHotKey / Karabiner installed

• AutoHotKey (Windows)
• Karabiner (macOS)

Other keyboard-related software installed

No response

Additional Context

The converter updates are minor changes to resolve missing LED pins during compilation.