x86: apic: simplify secondary CPU wakeup methods

Impact: cleanup

- rename apic->wakeup_cpu  to apic->wakeup_secondary_cpu, to
  make it apparent that this is an SMP-only method

- handle NULL ->wakeup_secondary_cpus to mean the default INIT
  wakeup sequence - this allows simplification of the APIC
  driver templates.

Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 0fbf6f1..4ef949c 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -313,7 +313,7 @@
 	void (*send_IPI_self)(int vector);
 
 	/* wakeup_secondary_cpu */
-	int (*wakeup_cpu)(int apicid, unsigned long start_eip);
+	int (*wakeup_secondary_cpu)(int apicid, unsigned long start_eip);
 
 	int trampoline_phys_low;
 	int trampoline_phys_high;
@@ -344,13 +344,6 @@
 #ifdef CONFIG_SMP
 extern atomic_t init_deasserted;
 extern int wakeup_secondary_cpu_via_nmi(int apicid, unsigned long start_eip);
-extern int wakeup_secondary_cpu_via_init(int apicid, unsigned long start_eip);
-#else
-static inline int
-wakeup_secondary_cpu_via_init(int apicid, unsigned long start_eip)
-{
-	return 0;
-}
 #endif
 
 static inline u32 apic_read(u32 reg)