drm/amdgpu: enable ih clock gating for navi12

enables ih clock gating
Signed-off-by: Xiaojie Yuan <xiaojie.yuan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -646,6 +646,7 @@ static int nv_common_early_init(void *handle)
 			AMD_CG_SUPPORT_GFX_CGCG |
 			AMD_CG_SUPPORT_GFX_CP_LS |
 			AMD_CG_SUPPORT_GFX_RLC_LS |
+			AMD_CG_SUPPORT_IH_CG |
 			AMD_CG_SUPPORT_HDP_MGCG |
 			AMD_CG_SUPPORT_HDP_LS |
 			AMD_CG_SUPPORT_SDMA_MGCG |