dt-bindings: arm: bcm: document TP-Link Archer C2300 binding

One more BCM4906 based device.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

Documentation/devicetree/bindings/arm/bcm/brcm,bcm4908.yaml

@@ -21,6 +21,7 @@ properties:
         items:
           - enum:
               - netgear,r8000p
+              - tplink,archer-c2300-v1
           - const: brcm,bcm4906
           - const: brcm,bcm4908