[Why]
DcGfxBase case was not accounted for in hubp program tiling functions,
causing tiling corruption on PNP.
[How]
Add handling for DcGfxBase so that tiling gets properly cleared.
Reviewed-by: Charlene Liu <charlene.liu@amd.com> Signed-off-by: Nicholas Carbones <ncarbone@amd.com> Signed-off-by: Tom Chung <chiahsuan.chung@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>