[S390] fix vmlinux link when CONFIG_SYSIPC=n

Fix the following compile error:

  CC      init/version.o
  LD      init/built-in.o
  LD      .tmp_vmlinux1
arch/s390/kernel/built-in.o(.text+0xdba4): In function `sys32_ipc':
: undefined reference to `compat_sys_semtimedop'
arch/s390/kernel/built-in.o(.text+0xdbee): In function `sys32_ipc':
: undefined reference to `compat_sys_semctl'
arch/s390/kernel/built-in.o(.text+0xdc08): In function `sys32_ipc':
: undefined reference to `compat_sys_msgsnd'
arch/s390/kernel/built-in.o(.text+0xdc30): In function `sys32_ipc':
: undefined reference to `compat_sys_msgrcv'
arch/s390/kernel/built-in.o(.text+0xdc58): In function `sys32_ipc':
: undefined reference to `compat_sys_msgctl'
arch/s390/kernel/built-in.o(.text+0xdc76): In function `sys32_ipc':
: undefined reference to `compat_sys_shmat'
arch/s390/kernel/built-in.o(.text+0xdcb0): In function `sys32_ipc':
: undefined reference to `compat_sys_shmctl'
make: *** [.tmp_vmlinux1] Error 1

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>