rfkill: Fix compilation when PM is disabled

Add config macros for RFKILL_PM to fix compilation when
CONFIG_PM is disabled

Change-Id: I9fba48fb02d671885665354091101f3813426f57
Signed-off-by: Chintan Pandya <cpandya@codeaurora.org>
diff --git a/include/linux/rfkill.h b/include/linux/rfkill.h
index c6c6084..3d049ab 100644
--- a/include/linux/rfkill.h
+++ b/include/linux/rfkill.h
@@ -199,8 +199,11 @@
  * NOTE: not necessary for suspend/resume -- in that case the
  * core stops polling anyway
  */
+#ifdef CONFIG_RFKILL_PM
 void rfkill_resume_polling(struct rfkill *rfkill);
-
+#else
+static inline void rfkill_resume_polling(struct rfkill *rfkill) { }
+#endif
 
 /**
  * rfkill_unregister - Unregister a rfkill structure.