[media] cx25821: fix sparse warning

drivers/media/pci/cx25821/cx25821-video-upstream.c:334:25: warning: incorrect type in argument 2 (different address spaces)

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