split some rtc funcs out of hwclock and into an rtc header/lib so that the new rtcwake applet as well as hwclock can utilize the same code
diff --git a/util-linux/Config.in b/util-linux/Config.in
index e97f840..d1688e8 100644
--- a/util-linux/Config.in
+++ b/util-linux/Config.in
@@ -458,6 +458,12 @@
 	help
 	  This allows you to parse /proc/profile for basic profiling.
 
+config RTCWAKE
+	bool "rtcwake"
+	default n
+	help
+	  Enter a system sleep state until specified wakeup time.
+
 config SETARCH
 	bool "setarch"
 	default n