powerpc/ps3: Add __init to ps3_smp_probe

Add an __init annotation to the ps3_smp_probe() routine.
Fixes build warnings like these when
CONFIG_DEBUG_SECTION_MISMATCH=y:

 WARNING: Section mismatch in reference from the function .ps3_smp_probe()
Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/ps3/smp.c

@@ -57,7 +57,7 @@ static void ps3_smp_message_pass(int cpu, int msg)
 			" (%d)\n", __func__, __LINE__, cpu, msg, result);
 }
 
-static int ps3_smp_probe(void)
+static int __init ps3_smp_probe(void)
 {
 	int cpu;