Bring back the IO Functions definitions.

[elbric0]

I suggest to bring back the IO Functions definitions. I think they are useful because they avoid us to open the MCU doc to check what is the IOF number for a particular peripheral and I think they are more meaningful when reading the code. Example: If I need to assign a pin to the UART, I prefer to write Set_IO_Function (P16, IOF_UART0); than Set_IO_Function (P16, IOF0);.

[CLAassistant]

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[Fabien-Chouteau]

Thanks @elbric0 !