dt-bindings: net: Add Davicom dm9051 SPI ethernet controller

This is a new yaml base data file for configure davicom dm9051 with
device tree

Signed-off-by: Joseph CHAMG <josright123@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>