[POWERPC] Implement clockevents driver for powerpc

This registers a clock event structure for the decrementer and turns
on CONFIG_GENERIC_CLOCKEVENTS, which means that we now don't need
most of timer_interrupt(), since the work is done in generic code.
For secondary CPUs, their decrementer clockevent is registered when
the CPU comes up (the generic code automatically removes the
clockevent when the CPU goes down).

Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/time.h b/include/asm-powerpc/time.h
index fa331da..f058955 100644
--- a/include/asm-powerpc/time.h
+++ b/include/asm-powerpc/time.h
@@ -245,6 +245,7 @@
 #define snapshot_timebases()			do { } while (0)
 #endif
 
+extern void secondary_cpu_time_init(void);
 extern void iSeries_time_init_early(void);
 
 #endif /* __KERNEL__ */