[media] v4l: ti-vpe: Allow DMABUF buffer type support

[media] v4l: ti-vpe: Allow DMABUF buffer type support

For OMAP and DRA7x, we generally allocate video and graphics buffers through
omapdrm since the corresponding omap-gem driver provides DMM-Tiler backed
contiguous buffers. omapdrm is a dma-buf exporter. These buffers are used by
other drivers in the video pipeline.

Add VB2_DMABUF flag to the io_modes of the vb2 output and capture queues. This
allows the driver to import dma shared buffers.

Reviewed-by: Hans Verkuil <[email protected]>
Signed-off-by: Archit Taneja <[email protected]>
Signed-off-by: Kamil Debski <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>