of: irq: Ignore disabled intc's when searching map

When searching the interrupt map, if a matched parent is disabled, just
ignore it and move on with the search.

This allows for specifying connection of a single device IRQ to
multiple interrupt controllers via the interrupt map schema. This change
allows for selection of the active interrupt controller via the already
existing status = "disabled" mechanism.
Signed-off-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Acked-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NRob Herring <rob.herring@calxeda.com>

drivers/of/irq.c

@@ -217,6 +217,9 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
 				goto fail;
 			}
 
+			if (!of_device_is_available(newpar))
+				match = 0;
+
 			/* Get #interrupt-cells and #address-cells of new
 			 * parent
 			 */