[media] media: davinci: vpif_capture: drop check __KERNEL__

Drops check for #ifdef __KERNEL__, because this header is a Kernel
only header, where this define is always true.

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>