MIPS: SMP: Remove plat_smp_ops cpus_done method.

Nothing was using the method and there isn't any need for this hook.  This
leaves smp_cpus_done() empty for the moment.

As suggested by Paul Bolle <pebolle@tiscali.nl>.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/cmp.h

@@ -10,7 +10,6 @@ extern void cmp_smp_setup(void);
 extern void cmp_smp_finish(void);
 extern void cmp_boot_secondary(int cpu, struct task_struct *t);
 extern void cmp_init_secondary(void);
-extern void cmp_cpus_done(void);
 extern void cmp_prepare_cpus(unsigned int max_cpus);
 
 /* This is platform specific */