dt-bindings: i2c: nxp,pnx-i2c: allow clocks property

Allow clocks property to fix below CHECK_DTB warnings:
  arch/arm/boot/dts/nxp/lpc/lpc3250-ea3250.dtb: i2c@300 (nxp,pnx-i2c): Unevaluated properties are not allowed ('clocks' was unexpected)

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20250624200444.2514331-1-Frank.Li@nxp.com

Author: nxpfrankli

Documentation/devicetree/bindings/i2c/nxp,pnx-i2c.yaml

@@ -22,6 +22,9 @@ properties:
   interrupts:
     maxItems: 1
 
+  clocks:
+    maxItems: 1
+
   clock-frequency:
     default: 100000