dts: bindings: update renesas rzt2m gpio bindings to handle interrupts

Add irqs to rzt2m gpio bindings in order to add interrupt support to rzt2m
gpio driver and adds common gpio node to store interrupt config (irqs are
shared between ports)

Signed-off-by: Jakub Michalski <jmichalski@internships.antmicro.com>

dts/bindings/gpio/renesas,rzt2m-gpio-common.yaml

@@ -0,0 +1,11 @@
+# Copyright (c) 2024 Antmicro <www.antmicro.com>
+# SPDX-License-Identifier: Apache-2.0
+description: Renesas RZT2M GPIO common
+
+compatible: "renesas,rzt2m-gpio-common"
+
+include: base.yaml
+
+properties:
+  interrupts:
+    required: true

dts/bindings/gpio/renesas,rzt2m-gpio.yaml

@@ -13,6 +13,10 @@ properties:
   "#gpio-cells":
     const: 2
 
+  irqs:
+    type: array
+    description: pin-irq pairs
+
 gpio-cells:
   - pin
   - flags