x86_64: prepare shared kernel/syscall.c

EXTRA_AFLAGS	:= -traditional

obj-y	:= process_64.o signal_64.o entry_64.o traps_64.o irq_64.o \

		ptrace_64.o time_64.o ioport_64.o ldt_64.o setup_64.o i8259_64.o sys_x86_64.o \

		x8664_ksyms_64.o i387_64.o syscall.o vsyscall_64.o \

		x8664_ksyms_64.o i387_64.o syscall_64.o vsyscall_64.o \

		setup64.o bootflag.o e820_64.o reboot_64.o quirks.o i8237.o \

		pci-dma_64.o pci-nommu_64.o alternative.o hpet_64.o tsc_64.o bugs_64.o \

		perfctr-watchdog.o