Draft RP2350 RISC-V cores support

Hi, here you can find  draft pull request for pico2 board with rp2350 running  on RISC-V cores. https://github.com/apache/nuttx/pull/16424 Please test and share the feedback. Thank you. -- Serg Podtynnyi

Raspberry Pi 4B SPI driver

Hello everyone! I've opened a PR for an SPI driver for the BCM2711 (Raspberry Pi 4B chip) here: https://github.com/apache/nuttx/pull/16428 I would appreciate any review, especially if someone has a Pi 4B and a breadboard SPI device they can try this out on. Unfortunately it appears only the SPI