dt-bindings: pinctrl: renesas,rzg2l-pinctrl: Document the properties to handle GPIO IRQ

Document the required properties to handle GPIO IRQ.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220707182314.66610-6-prabhakar.mahadev-lad.rj@bp.renesas.com

Documentation/devicetree/bindings/pinctrl/renesas,rzg2l-pinctrl.yaml

@@ -47,6 +47,17 @@ properties:
   gpio-ranges:
     maxItems: 1
 
+  interrupt-controller: true
+
+  '#interrupt-cells':
+    const: 2
+    description:
+      The first cell contains the global GPIO port index, constructed using the
+      RZG2L_GPIO() helper macro in <dt-bindings/pinctrl/rzg2l-pinctrl.h> and the
+      second cell is used to specify the flag.
+      E.g. "interrupts = <RZG2L_GPIO(43, 0) IRQ_TYPE_EDGE_FALLING>;" if P43_0 is
+      being used as an interrupt.
+
   clocks:
     maxItems: 1
 
@@ -110,6 +121,8 @@ required:
   - gpio-controller
   - '#gpio-cells'
   - gpio-ranges
+  - interrupt-controller
+  - '#interrupt-cells'
   - clocks
   - power-domains
   - resets
@@ -126,6 +139,8 @@ examples:
             gpio-controller;
             #gpio-cells = <2>;
             gpio-ranges = <&pinctrl 0 0 392>;
+            interrupt-controller;
+            #interrupt-cells = <2>;
             clocks = <&cpg CPG_MOD R9A07G044_GPIO_HCLK>;
             resets = <&cpg R9A07G044_GPIO_RSTN>,
                      <&cpg R9A07G044_GPIO_PORT_RESETN>,