ARM: dts: dra76-evm: remove ov5640

DRA76 EVM boards are not shipped with OV5640 sensor module, it is a
separate purchase. OV5640 module is also just one of the possible
sensors or capture boards you can connect.

However, for some reason, OV5640 has been added to the board dts file,
making it cumbersome to use other sensors.

Remove the OV5640 from the dts file so that it is easy to use other
sensors via DT overlays.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>