ppc: Minor smp changes for consistency with ppc64

This makes platform code use the smp_ops variable directly instead
of ppc_md.smp_ops, removes the two unused `data' and `wait' arguments
from the *_message_pass() functions, and removes the call to the
never-implemented smp_ops->space_timers() function.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/ppc/platforms/prep_setup.c b/arch/ppc/platforms/prep_setup.c
index 490ff17..9e5637e 100644
--- a/arch/ppc/platforms/prep_setup.c
+++ b/arch/ppc/platforms/prep_setup.c
@@ -1160,6 +1160,6 @@
 #endif
 
 #ifdef CONFIG_SMP
-	ppc_md.smp_ops		 = &prep_smp_ops;
+	smp_ops			 = &prep_smp_ops;
 #endif /* CONFIG_SMP */
 }