[media] s5c73m3: fix a sparse warning

drivers/media/i2c/s5c73m3/s5c73m3-core.c:170:39: warning: incorrect type in argument 1 (different base types)
drivers/media/i2c/s5c73m3/s5c73m3-core.c:170:39:    expected restricted __be16 const [usertype] *p
drivers/media/i2c/s5c73m3/s5c73m3-core.c:170:39:    got unsigned short [usertype] *<noident>

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>