sunxi-mali-mainline-driver: new package

sunxi-mali-mainline-driver: new package

Add allwinner mali kernel driver package.  Used in combination with
userspace Allwinner openGL libraries, it gives possibility to use 3D openGL
SoC acceleration.

[Peter: Rename to sunxi-mali-mainline-driver.  Use revision selection from
	sunxi-mali-mainline package.  Depend on that package and default to
	y if dependencies are met. Tweak Linux config]
Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>