powerpc: Drop return value of smp_ops->probe()

smp_ops->probe() is currently supposed to return the number of cpus in
the system.

The last actual usage of the value was removed in May 2007 in e147ec8f1808
"[POWERPC] Simplify smp_space_timers". We still passed the value around
until June 2010 when even that was finally removed in c1aa687d499a
"powerpc: Clean up obsolete code relating to decrementer and timebase".

So drop that requirement, probe() now returns void, and update all
implementations.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 7c19959..825663c 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -42,7 +42,7 @@
 #ifdef CONFIG_PPC_SMP_MUXED_IPI
 	void  (*cause_ipi)(int cpu, unsigned long data);
 #endif
-	int   (*probe)(void);
+	void  (*probe)(void);
 	int   (*kick_cpu)(int nr);
 	void  (*setup_cpu)(int nr);
 	void  (*bringup_done)(void);
@@ -174,7 +174,7 @@
 
 extern int smt_enabled_at_boot;
 
-extern int smp_mpic_probe(void);
+extern void smp_mpic_probe(void);
 extern void smp_mpic_setup_cpu(int cpu);
 extern int smp_generic_kick_cpu(int nr);
 extern int smp_generic_cpu_bootable(unsigned int nr);