m68k: Convert m68k to use read/update_persistent_clock

This patch converts the m68k architecture to use the generic
read_persistent_clock and update_persistent_clock interfaces, reducing
the amount of arch specific code we have to maintain, and allowing for
further cleanups in the future.

I have not built or tested this patch, so help from arch maintainers
would be appreciated.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1267675049-12337-12-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/m68k/kernel/time.c

@@ -73,21 +73,24 @@ static irqreturn_t timer_interrupt(int irq, void *dummy)
 	return IRQ_HANDLED;
 }
 
-void __init time_init(void)
+void read_persistent_clock(struct timespec *ts)
 {
 	struct rtc_time time;
+	ts->tv_sec = 0;
+	ts->tv_nsec = 0;
 
 	if (mach_hwclk) {
 		mach_hwclk(0, &time);
 
 		if ((time.tm_year += 1900) < 1970)
 			time.tm_year += 100;
-		xtime.tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
+		ts->tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
 				      time.tm_hour, time.tm_min, time.tm_sec);
-		xtime.tv_nsec = 0;
 	}
-	wall_to_monotonic.tv_sec = -xtime.tv_sec;
+}
 
+void __init time_init(void)
+{
 	mach_sched_init(timer_interrupt);
 }