[U-Boot] rpi: Enable command bmp

[Alexander Graf]

> This patch enables the bmp command (with gzip support enabled) on all
> Raspberry Pi boards.
> 
> The value of CONFIG_SYS_VIDEO_LOGO_MAX_SIZE (required by
> CONFIG_VIDEO_BMP_GZIP) is set to match resolution of the "official"
> 7 inch LCD.
> 
> Signed-off-by: Adam Heinrich <adam at adamh.cz>
> Cc: Alexander Graf <agraf at suse.de>

Thanks, applied to rpi-next

Alex