use a tagged register for the frame buffer reference
use a tagged register for the frame buffer reference

Change-Id: I8e90548d229a4e1574efe6c8268f9fc15c074a66

hanw/connectal,cambridgehackers/connectal,chenm001/connectal,cambridgehackers/connectal,chenm001/connectal,hanw/connectal,csail-csg/connectal,chenm001/connectal,8l/connectal,8l/connectal,8l/connectal,csail-csg/connectal,cambridgehackers/connectal,8l/connectal,8l/connectal,chenm001/connectal,hanw/connectal,csail-csg/connectal,hanw/connectal,hanw/connectal,chenm001/connectal,csail-csg/connectal,cambridgehackers/connectal,csail-csg/connectal,cambridgehackers/connectal