drm: add bit depth parsing

EDID 1.4 digital monitors report the bit depth supported in the input
field.  Add support for parsing this out and storing the info in the
display_info structure for use by drivers.

[airlied: tweaked to fix inter-patch dependency]
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index d94684b..ee1cb70 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -198,6 +198,7 @@
 	unsigned int min_vfreq, max_vfreq;
 	unsigned int min_hfreq, max_hfreq;
 	unsigned int pixel_clock;
+	unsigned int bpc;
 
 	enum subpixel_order subpixel_order;