arm: gic: create empty stub gic_set_wake when !CONFIG_PM

Return success when CONFIG_PM is not defined instead of
returning failure.

Change-Id: Ibbdde7460d68d49d0554d88d77ddef3bec01508c
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index 8996f06..786f4fa 100644
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -331,7 +331,10 @@
 }
 
 #else
-#define gic_set_wake	NULL
+static int gic_set_wake(struct irq_data *d, unsigned int on)
+{
+	return 0;
+}
 #endif
 
 static void gic_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)