media: dt-bindings: i2c: Add Rohm BU64754 bindings

Add YAML device tree bindings for the ROHM BU64754 VCM Motor Driver for
Camera Autofocus.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>