STM32G0xx patches

[mobyfab]

Hello,

I'm submitting a couple patches to get more features out of the G0.

First is to fix CRC defines (they all have CRC)
Second is to add a weak IRQ handler definition for USB-C PD.

For the second patch, the implementation is minimal (we don't have UCPD in stm32_registry.h) but it should work for everyone since it's a weak stub.

[Giovanni]

Hi,

The patch is problematic because it uses a GCC-specific attribute, the code is supposed to be compiler-agnostic.

Giovanni

[Giovanni]

I added the CRC fix, I am working on a proper shared handler like it is done for USARTs etc, it should be ready later today.

Giovanni

[Giovanni]

Hi,

I added a shared handler, see stm32_usb1_ucpd1_2.inc to see the general direction for shared IRQs, it is not yet enabled on G0 because I need to update all mcuconf.h files 1st.

Giovanni