dt-bindings: display: bridge: nxp,tda998x: Add missing clocks

Some TDA998x variants (e.g. TDA19988) have an OSC_IN pin, to connect
an external oscillator circuit or clock source.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/2b66577296583a6787f770f0eb13c42a6b50768b.1768233569.git.geert+renesas@glider.be
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Author: geertu

Documentation/devicetree/bindings/display/bridge/nxp,tda998x.yaml

@@ -19,6 +19,9 @@ properties:
   interrupts:
     maxItems: 1
 
+  clocks:
+    maxItems: 1
+
   video-ports:
     $ref: /schemas/types.yaml#/definitions/uint32
     default: 0x230145