of/irq: make of_irq_find_parent static

of_irq_find_parent has no users outside of of_irq.c, so it does not make
sense to expose it in of_irq.h. Therefore remove the prototype and dummy
implmeentation and make the function static instead.
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/of/irq.c

@@ -53,7 +53,7 @@ EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
  * Returns a pointer to the interrupt parent node, or NULL if the interrupt
  * parent could not be determined.
  */
-struct device_node *of_irq_find_parent(struct device_node *child)
+static struct device_node *of_irq_find_parent(struct device_node *child)
 {
 	struct device_node *p;
 	const __be32 *parp;

include/linux/of_irq.h

@@ -77,7 +77,6 @@ static inline void of_msi_configure(struct device *dev, struct device_node *np)
  * so declare it here regardless of the CONFIG_OF_IRQ setting.
  */
 extern unsigned int irq_of_parse_and_map(struct device_node *node, int index);
-extern struct device_node *of_irq_find_parent(struct device_node *child);
 
 #else /* !CONFIG_OF */
 static inline unsigned int irq_of_parse_and_map(struct device_node *dev,
@@ -85,11 +84,6 @@ static inline unsigned int irq_of_parse_and_map(struct device_node *dev,
 {
 	return 0;
 }
-
-static inline void *of_irq_find_parent(struct device_node *child)
-{
-	return NULL;
-}
 #endif /* !CONFIG_OF */
 
 #endif /* __OF_IRQ_H */