Fix the following h8300 build failures:

  arch/h8300/kernel/ptrace_h.c: In function ‘trace_trap’:
  arch/h8300/kernel/ptrace_h.c:253:3: error: implicit declaration of function ‘force_sig’
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: uclinux-h8-devel@lists.sourceforge.jp
Fixes: c3edc401 ("sched/headers: Move task_struct::signal and ...")
Link: http://lkml.kernel.org/r/1488738434-3504-1-git-send-email-linux@roeck-us.netSigned-off-by: Ingo Molnar <mingo@kernel.org>