imx-base.inc: Add 'use-mainline-bsp' override support
The 'use-mainline-bsp' makes use of
MAACHINEOVERRIDES_EXTENDER_FILTER_OUT variable and currently filters
out the i.MX 6 and i.MX 7 overrides, ensuring we use the pristine
support for all metadata.
This commit does most changes related to initial mainline support for
Etnaviv and Video4Linux VPU support using CODA.
Change-Id: Idcb3e4f9c3bc46d4c066dea3c0388f821ab2d3ec Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>