[ARM] 3794/1: S3C24XX: do not defined set_irq_wake when no CONFIG_PM

Patch from Ben Dooks

Do not define set_irq_wake as a real function if
the CONFIG_PM option is not set.

Fixes bug reported by Thomas Gleixner.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-s3c2410/irq.h

@@ -100,5 +100,10 @@ s3c_irqsub_ack(unsigned int irqno, unsigned int parentmask, unsigned int group)
 
 /* exported for use in arch/arm/mach-s3c2410 */
 
+#ifdef CONFIG_PM
 extern int s3c_irq_wake(unsigned int irqno, unsigned int state);
+#else
+#define s3c_irq_wake NULL
+#endif
+
 extern int s3c_irqext_type(unsigned int irq, unsigned int type);