drm/amdgpu: enable ih CG for dimgrey_cavefish

Set ih CG flag for dimgrey_cavefish.
Signed-off-by: NTao Zhou <tao.zhou1@amd.com>
Reviewed-by: NHawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

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

@@ -919,7 +919,8 @@ static int nv_common_early_init(void *handle)
 			AMD_CG_SUPPORT_MC_MGCG |
 			AMD_CG_SUPPORT_MC_LS |
 			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_VCN_DPG |
 			AMD_PG_SUPPORT_JPEG |