Hardware overlay on G965

[Maxim Levitsky]

I did some test here to discover whenever the G965 really
doesn't have an hardware overlay, and it turns out that docs are right
and G965 does support overlay.
(I mean all its features, like YUV, scaling, contrast/brightness,...)

I send two patches to enable it, first to fix some bugs, and second to actually
enable in on G965 only, since maybe other flavors of G965 doesn't have it,
(mobile version, G35 which is considered to be G965 like).

If you want to test it on this hardware, change HW_HAS_OVERLAY(pI810) in src/common.h
Plus you can comment out texture video support temporally to make sure overlay is used.
(Texture is first xv adapter, so it is picked up by most software)

Best regards,
	Maxim Levitsky