imx-gpu-g2d: new package

imx-gpu-g2d: new package

Up until now, the G2D libraries were included inside the imx-gpu-viv
package. However, since next version of the i.MX will use a new
hardware IP to do 2D rendering (DPU), the GPU 2D libraries have been
separated from the 3D GPU package.

Tested with the following commands:
 # /usr/share/examples/g2d_samples/g2d_multiblit_test
 # /usr/share/examples/g2d_samples/g2d_overlay_test
 # /usr/share/examples/g2d_samples/g2d_test
 # gst-launch-1.0 videotestsrc ! imxg2dvideosink

Signed-off-by: Gary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>