gstreamer1.0-plugins-bad: Build eglglessink for Raspberry Pi

The eglglessink needs to be built to target the Raspberry Pi or it will seg-fault in use.

Autoconf attempts to detect whether to build for RPi but there are some include files needed, the search path to which must be specified.

ref: raspberrypi/firmware#34

ref: raspberrypi/firmware#99

This patch adds the needed include paths and forces the plugin to be built for Raspberry Pi.

Change-Id: Iffa79dfa9d9e852848ab1ab70a58c124567b7298
Signed-off-by: Alex J Lennon <ajlennon@dynamicdevices.co.uk>

recipes-multimedia/gstreamer/gstreamer1.0-plugins-bad_1.2.3.bbappend

@@ -0,0 +1 @@
+EXTRA_OECONF += " CPPFLAGS='-I${STAGING_DIR_TARGET}/usr/include/interface/vcos/pthreads -I${STAGING_DIR_TARGET}/usr/include/interface/vmcs_host/linux' --with-egl-window-system=rpi"