x86_64: prepare shared kernel/irq.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86_64/kernel/Makefile

@@ -4,7 +4,7 @@
 
 extra-y 	:= head.o head64.o init_task.o vmlinux.lds
 EXTRA_AFLAGS	:= -traditional
-obj-y	:= process.o signal_64.o entry.o traps_64.o irq.o \
+obj-y	:= process.o signal_64.o entry.o traps_64.o irq_64.o \
 		ptrace_64.o time_64.o ioport_64.o ldt.o setup_64.o i8259_64.o sys_x86_64.o \
 		x8664_ksyms.o i387_64.o syscall.o vsyscall_64.o \
 		setup64.o bootflag.o e820_64.o reboot.o quirks.o i8237.o \