irqdomain: Make irq_domain_alloc_irqs_recursive available

We are soon going to need the MSI layer to call into the domain
allocators. Instead of open coding this, make the standard
irq_domain_alloc_irqs_recursive function available to the MSI
layer.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

include/linux/irqdomain.h

@@ -367,6 +367,9 @@ static inline int irq_domain_alloc_irqs(struct irq_domain *domain,
 	return __irq_domain_alloc_irqs(domain, -1, nr_irqs, node, arg, false);
 }
 
+extern int irq_domain_alloc_irqs_recursive(struct irq_domain *domain,
+					   unsigned int irq_base,
+					   unsigned int nr_irqs, void *arg);
 extern int irq_domain_set_hwirq_and_chip(struct irq_domain *domain,
 					 unsigned int virq,
 					 irq_hw_number_t hwirq,

kernel/irq/irqdomain.c

@@ -1125,9 +1125,9 @@ static void irq_domain_free_irqs_recursive(struct irq_domain *domain,
 	}
 }
 
-static int irq_domain_alloc_irqs_recursive(struct irq_domain *domain,
-					   unsigned int irq_base,
-					   unsigned int nr_irqs, void *arg)
+int irq_domain_alloc_irqs_recursive(struct irq_domain *domain,
+				    unsigned int irq_base,
+				    unsigned int nr_irqs, void *arg)
 {
 	int ret = 0;
 	struct irq_domain *parent = domain->parent;