defconfig: add beaglexm defconfig

add defconfig for BeagleBoard xM.
powervr: add powervr virtual package
ti-gfx: add new package

adds accelerated GPU support for the OMAP35xx, AM35xx, AM37xx, DM37xx,
AM387x, C6A814x, AM389x, C6A816x, and AM335x platforms.
qt: add powervr and opengl

Use the following to test:
/usr/share/qt/examples/opengl/hellogl_es2/hellogl_es2 -qws -display powervr
defconfigs: demo defconfig for showing sgx on beaglexm
gst1-plugins-bad: rework eglglessink for ti-gfx