[POWERPC] Add powerpc get/set_rtc_time interface to new generic rtc class

Add powerpc get/set_rtc_time interface to new generic rtc class. This
abstracts rtc chip specific code from the platform code for rtc-over-i2c
platforms.  Specific RTC chip support is now configured under
Device Drivers -> Real Time Clock. Setting time of day from the RTC
on startup is also configurable.

this time without the potentially platform breaking initcall.

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/time.h b/include/asm-powerpc/time.h
index 5785ac4..b051d4c 100644
--- a/include/asm-powerpc/time.h
+++ b/include/asm-powerpc/time.h
@@ -39,6 +39,10 @@
 extern void wakeup_decrementer(void);
 extern void snapshot_timebase(void);
 
+#ifdef CONFIG_RTC_CLASS
+extern int __init rtc_class_hookup(void);
+#endif
+
 /* Some sane defaults: 125 MHz timebase, 1GHz processor */
 extern unsigned long ppc_proc_freq;
 #define DEFAULT_PROC_FREQ	(DEFAULT_TB_FREQ * 8)
@@ -234,4 +238,4 @@
 #endif
 
 #endif /* __KERNEL__ */
-#endif /* __PPC64_TIME_H */
+#endif /* __POWERPC_TIME_H */