drm/amd/powerplay: modify the feature mask to enable gfx/soc dpm

So far, the gfx/soc dpm is enabled with feature mask set.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>