Platforms/RaspberryPi: Return GOP PixelInformation in QueryMode()

Return correct values of PixelInformation in QueryMode().

This fixes the QueryMode_Func failures reported by SCT tests at
https://github.com/pftf/RPi4/issues/73



Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Pete Batard <pete@akeo.ie>
Cc: Andrei Warkentin <awarkentin@vmware.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Samer El-Haj-Mahmoud <samer.el-haj-mahmoud@arm.com>
Reviewed-by: Andrei Warkentin <awarkentin@vmware.com>