dt-bindings: net: brcm,unimac-mdio: Update maintainers for binding

Add Doug and myself as maintainers since this binding is used by the
GENET Ethernet controller for its internal MDIO controller.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20211206180049.2086907-3-f.fainelli@gmail.comSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/net/brcm,unimac-mdio.yaml

@@ -7,6 +7,8 @@ $schema: http://devicetree.org/meta-schemas/core.yaml#
 title: Broadcom UniMAC MDIO bus controller
 
 maintainers:
+  - Doug Berger <opendmb@gmail.com>
+  - Florian Fainelli <f.fainelli@gmail.com>
   - Rafał Miłecki <rafal@milecki.pl>
 
 allOf: