cris: time: Cleanup of persistent clock stuff

- Remove update_persistent_clock(), as it does nothing now.
- Remove read_persistent_clock(), let it fall back to the weak version.

Cc: Mikael Starvik <[e-mail]>
Cc: John Stultz <[e-mail]>
Cc: Arnd Bergmann <[e-mail]>
Signed-off-by: Xunlei Pang <[e-mail]>
Acked-by: Rabin Vincent <[e-mail]>
Signed-off-by: Jesper Nilsson <[e-mail]>

arch/cris/Kconfig

···
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IOMAP
-	select GENERIC_CMOS_UPDATE
 	select MODULES_USE_ELF_RELA
 	select CLONE_BACKWARDS2
 	select OLD_SIGSUSPEND

arch/cris/kernel/time.c

···
 extern unsigned long loops_per_jiffy; /* init/main.c */
 unsigned long loops_per_usec;
 
-int set_rtc_mmss(unsigned long nowtime)
-{
-	D(printk(KERN_DEBUG "set_rtc_mmss(%lu)\n", nowtime));
-	return 0;
-}
-
-/* grab the time from the RTC chip */
-unsigned long get_cmos_time(void)
-{
-	return 0;
-}
-
-
-int update_persistent_clock(struct timespec now)
-{
-	return set_rtc_mmss(now.tv_sec);
-}
-
-void read_persistent_clock(struct timespec *ts)
-{
-	ts->tv_sec = 0;
-	ts->tv_nsec = 0;
-}
-
-
 extern void cris_profile_sample(struct pt_regs* regs);
 
 void