STM32N6570-DK support is added

[armusin]

The STM32N6570-DK board specific files are added, and the "Supported Boards" list is updated.

"examples/device/cdc_dual_ports" example was running on the board successfully with the limitation described below.

There is a feature/bug:
The example should be built with DEBUG=1 and without logs strongly (make BOARD=stm32n6570dk DEBUG=1 all), otherwise it does not work.

make BOARD=stm32n6570dk DEBUG=1 LOG=2 all
or
make BOARD=stm32n6570dk LOG=2 all
leads to the following log and the board is not enumerated properly.

USBD init on controller 1, speed = Auto
sizeof(usbd_device_t) = 56
sizeof(dcd_event_t) = 12
sizeof(tu_fifo_t) = 12
sizeof(tu_edpt_stream_t) = 20
CDC init
guid, gsnpsid, ghwcfg1, ghwcfg2, ghwcfg3, ghwcfg4
0x00005000, 0x4F54411A, 0x00000000, 0x228FE052, 0x03B882E8, 0xE2103E30
Highspeed UTMI+ PHY init
DMA = 0

Any advice on the issue would be appreciated.

[armusin]

Hi @hathach ,

The HIL tests are failed for the STM32H7 MCU, its code was untouched in the PR.
Could you please clarify what should be done on my side to proceed with the PR?

[hathach]

• LOG with uart can mess up timing, try to log with segger RTT to see if that improves
• HIL pool include lots of hardware, when they run simulateneously, usb can failed (timeout), it is ususally fixed by re-run the ci. Let me know when you think this PR is ready for review.

[Copilot]

Pull Request Overview

This PR adds support for the STM32N6570-DK development board to TinyUSB, including board-specific configuration files, hardware abstraction layer implementation, and documentation updates.

Key changes:

• Board configuration and build system files for STM32N6570-DK
• Hardware abstraction implementation with USB PD support via TCPP0203 chip
• Documentation update to include the new board in the supported boards list

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
hw/bsp/stm32n6/boards/stm32n6570dk/board.mk	Make-based build configuration for the board
hw/bsp/stm32n6/boards/stm32n6570dk/board.h	Board-specific hardware definitions and initialization code
hw/bsp/stm32n6/boards/stm32n6570dk/board.cmake	CMake-based build configuration for the board
hw/bsp/stm32n6/boards/stm32n6570dk/STM32N657XX_AXISRAM2_fsbl.ld	Linker script for memory layout configuration
docs/reference/boards.rst	Updates supported boards documentation to include STM32N6570-DK