[Feature] New support for the new STM32F746G-Discovery board

[inmarket]

Support has been added for the STM32F746G-Discovery board.

Currently this includes support for only the LCD controller. Other peripherals will be added as we test them.

As the STM32 m7 is a brand new processor you will need to update your software to versions that supports that cpu.

Software that may need to be updated include:

• Your compiler eg GCC
• Your ST-Link drivers (This board uses ST-Link V2.1)
• The firmware on the ST-Link V2.1 controller. V2.J24.M10 is the first version to work correctly for debugging, the latest is currently V2.J24.M11
• Your openocd version or other tool used for debugging. If you have trouble getting one to work ask us for the Windows version we compiled specifically for this.

This board and processor is not currently supported by many operating systems (it is too new) so our example makefile uses the raw32 GOS port with the STM32 cube library for the m7. Make sure you use the STMcubeM7 version of the cube library (not the m4 version).