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

This reverts commit 7a69af63e7.

As advised by David Brownell:

http://marc.theaimsgroup.com/?l=linux-kernel&m=116387226902131&w=2

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

include/asm-powerpc/time.h

@@ -39,10 +39,6 @@ extern void generic_calibrate_decr(void);
 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)