ARM: imx_v6_v7_defconfig: Enable staging video4linux drivers

Enable i.MX v4l2 media staging driver. For video capture on i.MX, the
video multiplexer subdev is required. On the SabreAuto, the ADV7180
video decoder is required along with i2c-mux-gpio. The Sabrelite
and SabreSD require the OV5640 and the SabreLite requires PWM clocks
for the OV5640.

Increase max zoneorder to allow larger video buffer allocations.

Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>