drm/amd/display: 3.2.308

This version brings along following fixes:
- Prune Invalid Modes for HDMI Output
- SPL Cleanup
- Fix brightness level not retained over reboot
- Remove inaccessible registers from DMU diagnostics

Acked-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Signed-off-by: Zaeem Mohamed <zaeem.mohamed@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: AMD-aric

drivers/gpu/drm/amd/display/dc/dc.h

@@ -55,7 +55,7 @@ struct aux_payload;
 struct set_config_cmd_payload;
 struct dmub_notification;
 
-#define DC_VER "3.2.307"
+#define DC_VER "3.2.308"
 
 #define MAX_SURFACES 3
 #define MAX_PLANES 6