ov8858 device tree addition

[Nicholas Roth <nicholas@xxxxxxxxxxxxx>]

All,

I've submitted a patch to linux-media that adds a driver for
the Omnivision OV8858 image sensor. Jacopo, a reviewer, asked
me to submit a device tree binding as well.

The relevant linux-media patch is entitled:
media: i2c: ov8858 Add driver for ov8858

Thanks,
-Nicholas