[TF-A] FIP and FCONF for STM32MP1

Hi everyone,

I've just pushed a series to support FIP and FCONF on STM32MP1 platform.

I haven't put any TF-A maintainers yet, but feel free to comment. Just be aware that I'll be out of office for the 3 and a half coming weeks, so I won't be able to push new patch sets. But I'll try to connect from time to time to answer questions, if any.

Best regards, Yann