drm/amd/powerplay: fix logic error.

the error lead powerplay can't get display info in DGPU case.
store_cc6_data just implement in APU.

Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/hardwaremanager.c b/drivers/gpu/drm/amd/powerplay/hwmgr/hardwaremanager.c
index fa208ad..efb77ed 100644
--- a/drivers/gpu/drm/amd/powerplay/hwmgr/hardwaremanager.c
+++ b/drivers/gpu/drm/amd/powerplay/hwmgr/hardwaremanager.c
@@ -306,10 +306,14 @@
 {
 	PHM_FUNC_CHECK(hwmgr);
 
-	if (hwmgr->hwmgr_func->store_cc6_data == NULL)
+	if (display_config == NULL)
 		return -EINVAL;
 
 	hwmgr->display_config = *display_config;
+
+	if (hwmgr->hwmgr_func->store_cc6_data == NULL)
+		return -EINVAL;
+
 	/* to do pass other display configuration in furture */
 
 	if (hwmgr->hwmgr_func->store_cc6_data)