Adding required ST-Ericsson changes to graphics.h

Pixel formats have been added to graphics.h (they used to be in
hardware.h). One is ST-Ericsson specific and the rest are just
added since they were there in GB.

Change-Id: Ib180a29a1fb0a57bae478dc9a3ba6607fa8cab23
Signed-off-by: Patrik Ryd <patrik.ryd@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/70894
Signed-off-by: Alin Jerpelea <jerpelea@gmail.com>