drm/amd/amdgpu: add IH cg support

IH cg 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>

drivers/gpu/drm/amd/amdgpu/nv.c

@@ -720,7 +720,8 @@ static int nv_common_early_init(void *handle)
 			AMD_CG_SUPPORT_VCN_MGCG |
 			AMD_CG_SUPPORT_JPEG_MGCG |
 			AMD_CG_SUPPORT_HDP_MGCG |
-			AMD_CG_SUPPORT_HDP_LS;
+			AMD_CG_SUPPORT_HDP_LS |
+			AMD_CG_SUPPORT_IH_CG;
 		adev->pg_flags = AMD_PG_SUPPORT_VCN |
 			AMD_PG_SUPPORT_JPEG;
 		adev->external_rev_id = adev->rev_id + 0x28;