[media] media: sh-vou: fix compilation breakage

[media] media: sh-vou: fix compilation breakage

A recent commit
commit f135a8a224294fa0f60ec1b8bc120813b7cfc804
Author: Hans Verkuil <hans.verkuil@cisco.com>
    [media] sh_vou: remove V4L2_FL_LOCK_ALL_FOPS
broke compilation of sh_vou.c:
drivers/media/platform/sh_vou.c: In function 'sh_vou_mmap':
drivers/media/platform/sh_vou.c:1227: error: 'vdev' undeclared (first use in this function)
drivers/media/platform/sh_vou.c:1227: error: (Each undeclared identifier is reported only once
drivers/media/platform/sh_vou.c:1227: error: for each function it appears in.)
drivers/media/platform/sh_vou.c: In function 'sh_vou_poll':
drivers/media/platform/sh_vou.c:1242: error: 'vdev' undeclared (first use in this function)
make[2]: *** [drivers/media/platform/sh_vou.o] Error 1
Add missing variable definitions.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>