sh: intc: Allocate subgroup virq backing desc directly.

This switches to using irq_alloc_desc() directly for subgroup IRQs.
We still need to call activate_irq() on these in order to make them
requestable, at least up until these get moved in to their own irq
domain..

Signed-off-by: Paul Mundt <[e-mail]>

drivers/sh/intc/virq.c

···
 		if (radix_tree_deref_retry(entry))
 			goto restart;
 
-		irq = create_irq();
+		irq = irq_alloc_desc(numa_node_id());
 		if (unlikely(irq < 0)) {
 			pr_err("no more free IRQs, bailing..\n");
 			break;
 		}
+
+		activate_irq(irq);
 
 		pr_info("Setting up a chained VIRQ from %d -> %d\n",
 			irq, entry->pirq);