drm/i915: Pass lane count to bxt_ddi_phy_calc_lane_optmin_mask()

Pass lane count to bxt_ddi_phy_calc_lane_optmin_mask() instead of having
it extract that number from a pipe_config to decouple the phy code from
intel_crtc_state.

Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/a4977e0207e594953c4f9d1b5f2ef972a8679e74.1475770848.git-series.ander.conselvan.de.oliveira@intel.com
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index fb18d69..1de0276 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -2190,9 +2190,9 @@ bool bxt_ddi_phy_verify_state(struct drm_i915_private *dev_priv,
 
 static uint8_t
 bxt_ddi_phy_calc_lane_lat_optim_mask(struct intel_encoder *encoder,
-				     struct intel_crtc_state *pipe_config)
+				     uint8_t lane_count)
 {
-	switch (pipe_config->lane_count) {
+	switch (lane_count) {
 	case 1:
 		return 0;
 	case 2:
@@ -2200,7 +2200,7 @@ bxt_ddi_phy_calc_lane_lat_optim_mask(struct intel_encoder *encoder,
 	case 4:
 		return BIT(3) | BIT(2) | BIT(0);
 	default:
-		MISSING_CASE(pipe_config->lane_count);
+		MISSING_CASE(lane_count);
 
 		return 0;
 	}
@@ -2417,7 +2417,7 @@ static bool intel_ddi_compute_config(struct intel_encoder *encoder,
 	if (IS_BROXTON(dev_priv) && ret)
 		pipe_config->lane_lat_optim_mask =
 			bxt_ddi_phy_calc_lane_lat_optim_mask(encoder,
-							     pipe_config);
+							     pipe_config->lane_count);
 
 	return ret;