arch/x86/irq: Purge useless handler declarations from hw_irq.h

arch/x86/include/asm/hw_irq.h contains declarations for the C-level handlers
called into directly from the IDT-referenced assembly stubs. These
declarations are never used as they are referenced from assembly only.

Furthermore, these declarations got their attributes wrong: there is no
'__irqentry' (parameter passing via stack) attached to them.

Also, the list of declarations isn't complete: none of the tracing-capable
variants is declared, for example.

Purge the handler declarations.
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/include/asm/hw_irq.h

@@ -168,20 +168,6 @@ extern atomic_t irq_mis_count;
 
 extern void elcr_set_level_irq(unsigned int irq);
 
-/* SMP */
-extern __visible void smp_apic_timer_interrupt(struct pt_regs *);
-extern __visible void smp_spurious_interrupt(struct pt_regs *);
-extern __visible void smp_x86_platform_ipi(struct pt_regs *);
-extern __visible void smp_error_interrupt(struct pt_regs *);
-#ifdef CONFIG_X86_IO_APIC
-extern asmlinkage void smp_irq_move_cleanup_interrupt(void);
-#endif
-#ifdef CONFIG_SMP
-extern __visible void smp_reschedule_interrupt(struct pt_regs *);
-extern __visible void smp_call_function_interrupt(struct pt_regs *);
-extern __visible void smp_call_function_single_interrupt(struct pt_regs *);
-#endif
-
 extern char irq_entries_start[];
 #ifdef CONFIG_TRACING
 #define trace_irq_entries_start irq_entries_start