Document the UCD90320 device tree binding.
Signed-off-by: Jim Wright <wrightj@linux.vnet.ibm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20191205232411.21492-2-wrightj@linux.vnet.ibm.comSigned-off-by: Guenter Roeck <linux@roeck-us.net>