Add VB2_DMABUF and VIDIOC_EXPBUF support. Also add VB2_USERPTR support
for the vmalloc DMA mode which was missing for no good reason.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NJonathan Corbet <corbet@lwn.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>