V4L/DVB (13469): Davinci VPFE Capture: Add support for Control ioctls

Added support for Control IOCTL,
        - s_ctrl
        - g_ctrl
        - queryctrl

Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>