m68knommu: modify timer init code to make it consistent with m68k code

With a few small changes we can make the m68knommu timer init code the
same as the m68k code. By using the mach_sched_init function pointer
and reworking the current timer initializers to keep track of the common
m68k timer_interrupt() handler we end up with almost identical code for
m68knommu.

This will allow us to more easily merge the mmu and non-mmu m68k time.c
in future patches.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>

arch/m68k/kernel/setup_no.c

@@ -48,6 +48,7 @@ EXPORT_SYMBOL(memory_end);
 char __initdata command_line[COMMAND_LINE_SIZE];
 
 /* machine dependent timer functions */
+void (*mach_sched_init)(irq_handler_t handler) __initdata = NULL;
 int (*mach_set_clock_mmss)(unsigned long);
 int (*mach_hwclk) (int, struct rtc_time*);