dt-bindings: interrupt-controller: ti,sci-intr: Fix missing reg property in the binding

Fix the following warning in dtbs_check
interrupt-controller@a00000: Unevaluated properties are not allowed ('reg' was unexpected)

Add the reg property in the schema.

Signed-off-by: Apurva Nandan <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Signed-off-by: Marc Zyngier <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.yaml

···
         1 = If intr supports edge triggered interrupts.
         4 = If intr supports level triggered interrupts.
 
+  reg:
+    maxItems: 1
+
   interrupt-controller: true
 
   '#interrupt-cells':