[media] saa7134: Fix sparse warnings by adding __user annotation

Adding a __user annotation fixes the following sparse warnings.
drivers/media/pci/saa7134/saa7134-video.c:1578:45: warning:
        incorrect type in initializer (different address spaces)
        drivers/media/pci/saa7134/saa7134-video.c:1578:45:
        expected struct v4l2_clip *clips
        drivers/media/pci/saa7134/saa7134-video.c:1578:45:
        got struct v4l2_clip [noderef] <asn:1>*clips
drivers/media/pci/saa7134/saa7134-video.c:1589:26: warning:
        incorrect type in assignment (different address spaces)
        drivers/media/pci/saa7134/saa7134-video.c:1589:26:
        expected struct v4l2_clip [noderef] <asn:1>*clips
        drivers/media/pci/saa7134/saa7134-video.c:1589:26:
        got struct v4l2_clip *clips

Signed-off-by: Emil Goode <emilgoode@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>