irqdomain: Introduce is_fwnode_irqchip helper

Since there will be several places checking if fwnode.type
is equal FWNODE_IRQCHIP, this patch adds a convenient function
for this purpose.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

kernel/irq/irqdomain.c

@@ -70,7 +70,7 @@ void irq_domain_free_fwnode(struct fwnode_handle *fwnode)
 {
 	struct irqchip_fwid *fwid;
 
-	if (WARN_ON(fwnode->type != FWNODE_IRQCHIP))
+	if (WARN_ON(!is_fwnode_irqchip(fwnode)))
 		return;
 
 	fwid = container_of(fwnode, struct irqchip_fwid, fwnode);