[media] v4l: Move s5p-fimc driver into Video capture devices

s5p-fimc now also implements a camera capture video node so move
it under the "Video capture devices" Kconfig menu. Also update
the entry to reflect the driver's coverage of EXYNOS4 SoCs and
separate the Makefile entry from the soc-camera drivers set.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>