sh: Kill off the global rtc_lock with extreme prejudice.

Now that all of the possible users for rtc_lock have gone away, it is no
longer necessary to keep this lock definition around.

This follows several other architectures that have either recently
dropped it or never supported it in the first place.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/time.c

@@ -17,7 +17,6 @@
 #include <linux/timex.h>
 #include <linux/sched.h>
 #include <linux/clockchips.h>
-#include <linux/mc146818rtc.h>	/* for rtc_lock */
 #include <linux/platform_device.h>
 #include <linux/smp.h>
 #include <linux/rtc.h>
@@ -27,10 +26,6 @@
 
 struct sys_timer *sys_timer;
 
-/* Move this somewhere more sensible.. */
-DEFINE_SPINLOCK(rtc_lock);
-EXPORT_SYMBOL(rtc_lock);
-
 /* Dummy RTC ops */
 static void null_rtc_get_time(struct timespec *tv)
 {