drm/i915: Parse the eDP link configuration from the vBIOS

First step, lets have a look at the values for troublesome panels and
see if they may be used to improve our link training.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 6fbaa63..4843d02 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3705,7 +3705,7 @@
 			else
 				temp |= PIPE_6BPC;
 		} else if (has_edp_encoder || (is_dp && intel_pch_has_edp(crtc))) {
-			switch (dev_priv->edp_bpp/3) {
+			switch (dev_priv->edp.bpp/3) {
 			case 8:
 				temp |= PIPE_8BPC;
 				break;