x86: rename the i8259_32/64.c leftovers to irqinit_32/64.c

The leftovers of the i8259 unification have nothing to do with i8259
at all. They contain interrupt init code and the i8259_xx name is just
misleading now.

Rename them to irqinit_32/64.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/Makefile

@@ -18,7 +18,7 @@ CFLAGS_tsc_64.o		:= $(nostackp)
 obj-y			:= process_$(BITS).o signal_$(BITS).o entry_$(BITS).o
 obj-y			+= traps_$(BITS).o irq_$(BITS).o
 obj-y			+= time_$(BITS).o ioport.o ldt.o
-obj-y			+= setup_$(BITS).o i8259.o i8259_$(BITS).o setup.o
+obj-y			+= setup_$(BITS).o i8259.o irqinit_$(BITS).o setup.o
 obj-$(CONFIG_X86_32)	+= sys_i386_32.o i386_ksyms_32.o
 obj-$(CONFIG_X86_64)	+= sys_x86_64.o x8664_ksyms_64.o
 obj-$(CONFIG_X86_64)	+= syscall_64.o vsyscall_64.o setup64.o