<L4 LL> do not use LL_GPIO_Init in AF mode without specifying Alternate Function
<L4 LL> do not use LL_GPIO_Init in AF mode without specifying Alternate Function

This was possible with SPL but no more with LL (and probably HAL)

Before this modification, we had some random issues and sometimes,
we were not able to use the debugger.

lancernet/Espruino,luetgendorf/Espruino,luetgendorf/Espruino,lancernet/Espruino,wilberforce/Espruino,wilberforce/Espruino,luetgendorf/Espruino,lancernet/Espruino,luetgendorf/Espruino,wilberforce/Espruino,wilberforce/Espruino,lancernet/Espruino,lancernet/Espruino,lancernet/Espruino,luetgendorf/Espruino,wilberforce/Espruino,lancernet/Espruino,luetgendorf/Espruino,luetgendorf/Espruino,wilberforce/Espruino,wilberforce/Espruino