drm/amd/amdgpu: add HDP mgcg and ls support

add HDP mgcg and ls support and verified

Signed-off-by: Kenneth Feng <kenneth.feng@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>