[media] cx25821: convert to vb2

This patch converts the cx25821 driver from the old videobuf framework to
the new vb2 framework.

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

diff --cc drivers/media/pci/cx25821/Kconfig
Simple merge

diff --cc drivers/media/pci/cx25821/cx25821-core.c
Simple merge

diff --cc drivers/media/pci/cx25821/cx25821-video.c
Simple merge

diff --cc drivers/media/pci/cx25821/cx25821.h
Simple merge