Enable the gfx base HW function of green_sardine.

v2: use apu flags
Signed-off-by: NPrike Liang <Prike.Liang@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NHuang Rui <ray.huang@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>