linux-phytec-ti

media: v4l2-mem2mem: add v4l2_m2m_last_buf()

This can be used to mark the last queued source buffer as the last
buffer.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>