Use VFE PIX input interface and do format conversion in VFE.

Supported input format is UYVY (single plane YUV 4:2:2) and
its different sample order variations.

Supported output formats are:
- NV12/NV21 (two plane YUV 4:2:0)
- NV16/NV61 (two plane YUV 4:2:2)
Signed-off-by: NTodor Tomov <todor.tomov@linaro.org>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>