dt-bindings: interrupt-controller: ti,irq-crossbar: Convert to DT schema

dt-bindings: interrupt-controller: ti,irq-crossbar: Convert to DT schema

Convert TI irq-crossbar binding from text format to DT schema.

As part of conversion following changes are made:
 - Add '#interrupt-cells' as a required property which was missing in
   text binding
 - As irq-crossbar is interrupt-controller. Move binding from
   bindings/arm/omap to bindings/interrupt-controller

Signed-off-by: Bhargav Joshi <j.bhargav.u@gmail.com>
Link: https://patch.msgid.link/20260612-crossbar-v3-1-266747bc2e86@gmail.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>