Support for the STM32L496VGTx series

[CzokNorris]

I use the STM32L496VGT6 which is a more and more popular microcontroller, but there is no support for this part in this project.

If someone knows how to add support, that would be great.

[fpistm]

Hi @CzokNorris
I've added this request to #722.
You will find a link to the wiki to add generic board support. You can also refer to PR adding board support as example.