drm/amd/display: Add DP2 Metrics

Why:
Log DP2 data to be used for debugging purposes

How:
Check the reported link rate of the DP connection and
translate it to the DP version.
Acked-by: Stylon Wang <stylon.wang@amd.com>
Signed-off-by: Austin Zheng <austin.zheng@amd.com>
Reviewed-by: Martin Leung <Martin.Leung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

 /*
- * Copyright 2012-14 Advanced Micro Devices, Inc.
+ * Copyright 2012-2023 Advanced Micro Devices, Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -60,7 +60,9 @@ struct dc_versions {
 };
 
 enum dp_protocol_version {
-	DP_VERSION_1_4,
+	DP_VERSION_1_4 = 0,
+	DP_VERSION_2_1,
+	DP_VERSION_UNKNOWN,
 };
 
 enum dc_plane_type {

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

@@ -61,7 +61,7 @@ enum dc_link_rate {
 	 */
 	LINK_RATE_UHBR10 = 1000,	// UHBR10 - 10.0 Gbps/Lane
 	LINK_RATE_UHBR13_5 = 1350,	// UHBR13.5 - 13.5 Gbps/Lane
-	LINK_RATE_UHBR20 = 2000,	// UHBR10 - 20.0 Gbps/Lane
+	LINK_RATE_UHBR20 = 2000,	// UHBR20 - 20.0 Gbps/Lane
 };
 
 enum dc_link_spread {