drm/amdgpu/display: properly guard the calls to swSMU functions

It's only applicable on newer asics.  We could end up here when
using DC on older asics like SI or KV.

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1170Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_pp_smu.c

@@ -106,7 +106,7 @@ bool dm_pp_apply_display_requirements(
 			adev->powerplay.pp_funcs->display_configuration_change(
 				adev->powerplay.pp_handle,
 				&adev->pm.pm_display_cfg);
-		else
+		else if (adev->smu.ppt_funcs)
 			smu_display_configuration_change(smu,
 							 &adev->pm.pm_display_cfg);
 
@@ -592,7 +592,7 @@ void pp_rv_set_wm_ranges(struct pp_smu *pp,
 	if (pp_funcs && pp_funcs->set_watermarks_for_clocks_ranges)
 		pp_funcs->set_watermarks_for_clocks_ranges(pp_handle,
 							   &wm_with_clock_ranges);
-	else
+	else if (adev->smu.ppt_funcs)
 		smu_set_watermarks_for_clock_ranges(&adev->smu,
 				&wm_with_clock_ranges);
 }