sabre: Use hdmi as primary display only if connected

Test if HDMI display is connected before setting it as primary display.
Otherwise set lvds as primary display. Test can be overridden by
setting video_interfaces env.

Change-Id: If52b3cd57fc2645296ae8595ce02ae608359f24a
Reviewed-by: Teemu Holappa <teemu.holappa@theqtcompany.com>

meta-fsl-extras/recipes/u-boot/u-boot-fslc/0001-Use-hdmi-as-primary-display-only-if-connected.patch

+From 734ccf82db363efddb960b1c4f7db4081f2fdd7c Mon Sep 17 00:00:00 2001
+From: Samuli Piippo <samuli.piippo@theqtcompany.com>
+Date: Thu, 18 Feb 2016 12:49:01 +0200
+Subject: [PATCH] Use hdmi as primary display only if connected
+
+Test if HDMI display is connected before setting it as primary display.
+Otherwise set lvds as primary display. Test can be overridden by
+setting video_interfaces env.
+---
+ include/configs/mx6sabre_common.h | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/include/configs/mx6sabre_common.h b/include/configs/mx6sabre_common.h
+index a8746a4..485f232 100644
+--- a/include/configs/mx6sabre_common.h
++++ b/include/configs/mx6sabre_common.h
+@@ -163,8 +163,16 @@
+ 	"video_args_lcd=setenv video_args $video_args " \
+ 		"video=mxcfb${fb}:dev=lcd,CLAA-WVGA,if=RGB666\0" \
+ 	"fb=0\0" \
+-	"video_interfaces=hdmi lvds lcd\0" \
++	"video_interfaces=\0" \
+ 	"video_args_script=" \
++        "if test -z \"${video_interfaces}\"; then " \
++            "i2c dev 1; " \
++            "if i2c probe 0x50; then " \
++                  "setenv video_interfaces hdmi lvds lcd; " \
++            "else " \
++                  "setenv video_interfaces lvds hdmi lcd; " \
++            "fi; " \
++        "fi; " \
+ 		"for v in ${video_interfaces}; do " \
+ 			"run video_args_${v}; " \
+ 			"setexpr fb $fb + 1; " \
+-- 
+1.9.1
+

meta-fsl-extras/recipes/u-boot/u-boot-fslc_2015.%.bbappend

@@ -22,4 +22,5 @@
 FILESEXTRAPATHS_append := "${THISDIR}/${PN}:"
 SRC_URI += " \
         file://0001-Updated-kernel-arguments-for-sabre-sd.patch \
+        file://0001-Use-hdmi-as-primary-display-only-if-connected.patch \
         "