dt-bindings: arm: optee: add interrupt property

Adds an optional interrupt property to the optee binding.

Reviewed-by: Sumit Garg <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Acked-by: Marc Zyngier <[e-mail]>
Signed-off-by: Jens Wiklander <[e-mail]>

Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.yaml

···
   compatible:
     const: linaro,optee-tz
 
+  interrupts:
+    maxItems: 1
+    description: |
+      This interrupt which is used to signal an event by the secure world
+      software is expected to be edge-triggered.
+
   method:
     enum: [smc, hvc]
     description: |
···
 
 examples:
   - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
     firmware  {
         optee  {
             compatible = "linaro,optee-tz";
             method = "smc";
+            interrupts = <GIC_SPI 187 IRQ_TYPE_EDGE_RISING>;
         };
     };