[S390] Remove TOPDIR from Makefile

This patch removes TOPDIR from arch/s390/kernel/Makefile.

Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NWANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/Makefile

@@ -31,7 +31,3 @@ S390_KEXEC_OBJS := machine_kexec.o crash.o
 S390_KEXEC_OBJS += $(if $(CONFIG_64BIT),relocate_kernel64.o,relocate_kernel.o)
 obj-$(CONFIG_KEXEC) += $(S390_KEXEC_OBJS)
 
-#
-# This is just to get the dependencies...
-#
-binfmt_elf32.o:	$(TOPDIR)/fs/binfmt_elf.c