[PATCH 7/9] board: stm32mp1: update readme

[Patrick DELAUNAY]

Hi,

> From: Patrick DELAUNAY <patrick.delaunay at st.com>
> Sent: mardi 28 janvier 2020 10:11
> 
> Update readme:
> - list the supported SOC and change family to STM32MP15x
> - add warning on OTP write and prerequisite:
>   check if MAC address is not yet provisioned.
> - Use filesize for mmc write command (avoid to write all partition
>   with ${partsize}). ${filesize} and ${partsize} are set by previous
>   load command.
> 
> Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
> ---

Applied to u-boot-stm32/master, thanks!

Regards
Patrick