db845c: Add rb5 support in db845c-userdebug build target

* Enabled multiple appended DTBs support to allow db845c
boot.img/vendor_boot.img to boot on rb5 as well.

* Introduced a vendor.hw property which will be used to run
device specific services.

* Folded Caleb's HDMI audio routing fix.

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Change-Id: I779d01946ae359d5c405d959419e29460083e5df
diff --git a/qcom/init.qcom.rc b/qcom/init.qcom.rc
index f97b502..38d8d00 100644
--- a/qcom/init.qcom.rc
+++ b/qcom/init.qcom.rc
@@ -1,3 +1,10 @@
+service set_hw /vendor/bin/set_hw.sh
+    class core
+    user root
+    group system
+    disabled
+    oneshot
+
 service qrtr-ns /vendor/bin/qrtr-ns -f 1
     class core
     user root
@@ -27,6 +34,7 @@
     oneshot
 
 on early-init
+    start set_hw
     exec - root -- /vendor/bin/qrtr-cfg 1
     start qrtr-ns