dts: bindings: gpio: silabs-siwx91x: New properties

1. silabs,port-count - Number of ports present in GPIO
   controller used for port validation in init function.
2. silabs,max-pin-usage-count - Maximum number of pins
   used as GPIO in a controller.

Signed-off-by: Sai Santhosh Malae <[email protected]>

Author: smalae

dts/bindings/gpio/silabs,siwx91x-gpio.yaml

@@ -11,6 +11,19 @@ properties:
   interrupts:
     required: true
 
+  silabs,port-count:
+    type: int
+    description: |
+        Number of ports present in the GPIO controller
+    required: true
+
+  silabs,max-pin-usage-count:
+    type: int
+    description: |
+        Maximum number of pins used as GPIO, not applicable for UULP nodes
+        For HP GPIO, range is between <1 to 64>
+        For ULP GPIO, range is between <1 to 16>
+
   silabs,ulp:
     type: boolean
     description: |