of/irq: Export of_irq_find_parent again

of_irq_find_parent was made static since it had no users outside of
of_irq.c. Export it again since we are going to use it again.

Signed-off-by: Carlo Caione <carlo@endlessm.com>
[robh: move of_irq_find_parent to correct ifdef section]
Signed-off-by: Rob Herring <robh@kernel.org>
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 902b89b..4fa916d 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -53,7 +53,7 @@
  * Returns a pointer to the interrupt parent node, or NULL if the interrupt
  * parent could not be determined.
  */
-static struct device_node *of_irq_find_parent(struct device_node *child)
+struct device_node *of_irq_find_parent(struct device_node *child)
 {
 	struct device_node *p;
 	const __be32 *parp;
@@ -77,6 +77,7 @@
 
 	return p;
 }
+EXPORT_SYMBOL_GPL(of_irq_find_parent);
 
 /**
  * of_irq_parse_raw - Low level interrupt tree parsing