dt-bindings: display: Add BCM2712 HDMI bindings

The BCM2712 HDMI controller uses a slightly different HDMI controller
than the BCM2711, and a completely different PHY.

Let's introduce a new compatible for it.

Signed-off-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241025-drm-vc4-2712-support-v2-3-35efa83c8fc0@raspberrypi.com
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml

@@ -14,6 +14,8 @@ properties:
     enum:
       - brcm,bcm2711-hdmi0
       - brcm,bcm2711-hdmi1
+      - brcm,bcm2712-hdmi0
+      - brcm,bcm2712-hdmi1
 
   reg:
     items: