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/set_hw.sh b/qcom/set_hw.sh
new file mode 100644
index 0000000..98f76c3
--- /dev/null
+++ b/qcom/set_hw.sh
@@ -0,0 +1,12 @@
+#! /vendor/bin/sh
+# Set vendor.hw property to run device specific services
+#
+# grep the device name from /proc/device-tree/compatible
+
+HW=`/vendor/bin/cat /proc/device-tree/compatible | /vendor/bin/grep rb5`
+
+if [ -z "${HW}" ]; then
+    setprop vendor.hw db845c
+else
+    setprop vendor.hw rb5
+fi