x86: remove duplicated declarations

Remove declarations which are made already in the appropriate header file.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

include/asm-x86/io_apic_64.h

@@ -129,10 +129,4 @@ extern int io_apic_set_pci_routing (int ioapic, int pin, int irq, int, int);
 
 extern int sis_apic_bug; /* dummy */ 
 
-void enable_NMI_through_LVT0 (void * dummy);
-
-extern spinlock_t i8259A_lock;
-
-extern int timer_over_8254;
-
 #endif