drm/radeon: Don't drop DP 2.7 Ghz link setup on some cards.

[ Upstream commit 459ee1c3 ]

As observed on Apple iMac10,1, DCE-3.2, RV-730,
link rate of 2.7 Ghz is not selected, because
the args.v1.ucConfig flag setting for 2.7 Ghz
gets overwritten by a following assignment of
the transmitter to use.

Move link rate setup a few lines down to fix this.
In practice this didn't have any positive or
negative effect on display setup on the tested
iMac10,1 so i don't know if backporting to stable
makes sense or not.
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

drivers/gpu/drm/radeon/atombios_encoders.c

@@ -892,8 +892,6 @@ atombios_dig_encoder_setup2(struct drm_encoder *encoder, int action, int panel_m
 			else
 				args.v1.ucLaneNum = 4;
 
-			if (ENCODER_MODE_IS_DP(args.v1.ucEncoderMode) && (dp_clock == 270000))
-				args.v1.ucConfig |= ATOM_ENCODER_CONFIG_DPLINKRATE_2_70GHZ;
 			switch (radeon_encoder->encoder_id) {
 			case ENCODER_OBJECT_ID_INTERNAL_UNIPHY:
 				args.v1.ucConfig = ATOM_ENCODER_CONFIG_V2_TRANSMITTER1;
@@ -910,6 +908,10 @@ atombios_dig_encoder_setup2(struct drm_encoder *encoder, int action, int panel_m
 				args.v1.ucConfig |= ATOM_ENCODER_CONFIG_LINKB;
 			else
 				args.v1.ucConfig |= ATOM_ENCODER_CONFIG_LINKA;
+
+			if (ENCODER_MODE_IS_DP(args.v1.ucEncoderMode) && (dp_clock == 270000))
+				args.v1.ucConfig |= ATOM_ENCODER_CONFIG_DPLINKRATE_2_70GHZ;
+
 			break;
 		case 2:
 		case 3: