drm/amd/display: read PSR-SU cap DPCD for specific panel

[why & how]
For some specific eDP panel, we'd check the PSR-SU cap during boot
by reading the vendor specific DPCD, otherwise it will cause to
false report the eDP panel which supports PSR-SU as an non-PSR-SU
panel.

- add the vendor specific DPCD address in ddc_service_types header
- if specific eDP panel detected, check vendor specific DPCD for
  PSR-SU cap

Reviewed-by: Aurabindo Jayamohanan Pillai <Aurabindo.Pillai@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: David Zhang <dingchen.zhang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/include/ddc_service_types.h

@@ -39,6 +39,8 @@
 #define DP_BRANCH_HW_REV_20 0x20
 
 #define DP_DEVICE_ID_38EC11 0x38EC11
+#define DP_FORCE_PSRSU_CAPABILITY 0x40F
+
 enum ddc_result {
 	DDC_RESULT_UNKNOWN = 0,
 	DDC_RESULT_SUCESSFULL,