x86, smp: refactor ->smp_callin_clear_local_apic() methods

Only NUMAQ does something substantial here, because it initializes
via NMIs (not via INIT as standard SMP startup) - so it needs to
reset the APIC.

 - extend the generic code to handle NULL methods

 - clear out dummy methods and replace them with NULL

 - clean up: remove wrapper macros, etc.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/numaq/wakecpu.h b/arch/x86/include/asm/numaq/wakecpu.h
index 884b95c..61d0a7d 100644
--- a/arch/x86/include/asm/numaq/wakecpu.h
+++ b/arch/x86/include/asm/numaq/wakecpu.h
@@ -8,9 +8,9 @@
 
 /*
  * Because we use NMIs rather than the INIT-STARTUP sequence to
- * bootstrap the CPUs, the APIC may be in a weird state. Kick it.
+ * bootstrap the CPUs, the APIC may be in a weird state. Kick it:
  */
-static inline void smp_callin_clear_local_apic(void)
+static inline void numaq_smp_callin_clear_local_apic(void)
 {
 	clear_local_APIC();
 }