x86: fix apic.c build error on latest git

Fix this by reintroducing asm/smp.h include in apic.c - later on
I will fix this by removing non-smp data from smp.h

Also fix the __inquire_remote_apic() prototype/inline.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/mach-default/mach_wakecpu.h

@@ -24,7 +24,13 @@ static inline void restore_NMI_vector(unsigned short *high, unsigned short *low)
 {
 }
 
+#ifdef CONFIG_SMP
 extern void __inquire_remote_apic(int apicid);
+#else /* CONFIG_SMP */
+static inline void __inquire_remote_apic(int apicid)
+{
+}
+#endif /* CONFIG_SMP */
 
 static inline void inquire_remote_apic(int apicid)
 {

arch/x86/kernel/apic.c

@@ -47,6 +47,7 @@
 #include <asm/proto.h>
 #include <asm/apic.h>
 #include <asm/i8259.h>
+#include <asm/smp.h>
 
 #include <mach_apic.h>
 #include <mach_apicdef.h>