[BUG] Recent modification broke raspberry pi pico nsh

### Description / Steps to reproduce the issue

Yashvi Shah reported me that she wasn't getting the nsh working on RaspberryPi Pico, then I tested here and in fact some recent modification broke the NSH.

@lupyuen is it possible to add RaspberryPi Pico to the automated test as well?

$ git clone -b 2.0.0 https://github.com/raspberrypi/pico-sdk.git

$ export PICO_SDK_PATH=/home/alan/pico-sdk

$ cd nuttxspace/nuttx

$ make distclean

You can use this script to find the board name after configure.sh just typing the inicial name of the board and pressing TAB

$ . tools/configure_completion.bash

$ ./tools/configure.sh raspberrypi-pico:nsh

$ make -j
flash: 144 KB 2 MB 7.03%
sram: 8224 B 264 KB 3.04%
Generating: nuttx.uf2
Done

Copy nuttx.uf2 to the virtual disk of raspberrypi pico and use a USB/Serial connected to GP0, GP1 and GND and reset the board, you will see the nsh is not accepting text and there is trash after the nuttx entry message (see attached image)

### On which OS does this issue occur?

[OS: BSD], [OS: Linux], [OS: Mac], [OS: Windows], [OS: Other]

### What is the version of your OS?

24.04

### NuttX Version

12.7 mainline

### Issue Architecture

[Arch: arm]

### Issue Area

[Area: Board support]

### Verification

- [X] I have verified before submitting the report.