drm/i915: Add the missing clonemask for display port on Ironlake

Add the missing clonemask for display port on Ironlake.
Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
cc: stable@kernel.org
Signed-off-by: NEric Anholt <eric@anholt.net>

drivers/gpu/drm/i915/intel_dp.c

@@ -1306,11 +1306,11 @@ intel_dp_init(struct drm_device *dev, int output_reg)
 	else
 		intel_output->type = INTEL_OUTPUT_DISPLAYPORT;
 
-	if (output_reg == DP_B)
+	if (output_reg == DP_B || output_reg == PCH_DP_B)
 		intel_output->clone_mask = (1 << INTEL_DP_B_CLONE_BIT);
-	else if (output_reg == DP_C)
+	else if (output_reg == DP_C || output_reg == PCH_DP_C)
 		intel_output->clone_mask = (1 << INTEL_DP_C_CLONE_BIT);
-	else if (output_reg == DP_D)
+	else if (output_reg == DP_D || output_reg == PCH_DP_D)
 		intel_output->clone_mask = (1 << INTEL_DP_D_CLONE_BIT);
 
 	if (IS_eDP(intel_output)) {