x86/apic: Implement single IPI for apic_noop

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Travis <travis@sgi.com>
Cc: Daniel J Blueman <daniel@numascale.com>
Link: http://lkml.kernel.org/r/20151104220849.455429817@linutronix.de

arch/x86/kernel/apic/apic_noop.c

@@ -30,6 +30,7 @@
 #include <asm/e820.h>
 
 static void noop_init_apic_ldr(void) { }
+static void noop_send_IPI(int cpu, int vector) { }
 static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { }
 static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { }
 static void noop_send_IPI_allbutself(int vector) { }
@@ -144,6 +145,7 @@ struct apic apic_noop = {
 
 	.cpu_mask_to_apicid_and		= flat_cpu_mask_to_apicid_and,
 
+	.send_IPI			= noop_send_IPI,
 	.send_IPI_mask			= noop_send_IPI_mask,
 	.send_IPI_mask_allbutself	= noop_send_IPI_mask_allbutself,
 	.send_IPI_allbutself		= noop_send_IPI_allbutself,