ARM: dts: imx7s-warp: add ov2680 sensor node

Warp7 comes with a Omnivision OV2680 sensor, add the node here to make
complete the camera data path for this system. Add the needed regulator
to the analog voltage supply, the port and endpoints in mipi_csi node
and the pinctrl for the reset gpio.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>