dt-bindings: arm: bcm: Add bindings for Buffalo WZR-1166DHP(2)

Add two more Northstar devices based on the BCM4708 SoC. Linux already
contains DTS files for both.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230602153657.11362-1-zajec5@gmail.comSigned-off-by: Florian Fainelli <florian.fainelli@broadcom.com>

Documentation/devicetree/bindings/arm/bcm/brcm,bcm4708.yaml

@@ -25,6 +25,8 @@ properties:
           - enum:
               - asus,rt-ac56u
               - asus,rt-ac68u
+              - buffalo,wzr-1166dhp
+              - buffalo,wzr-1166dhp2
               - buffalo,wzr-1750dhp
               - linksys,ea6300-v1
               - linksys,ea6500-v2