sh: Fix up signal_64 conflicting handle_signal() definition.

Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/kernel/signal_64.c

@@ -43,6 +43,10 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
+static void
+handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
+		sigset_t *oldset, struct pt_regs * regs);
+
 /*
  * Note that 'init' is a special process: it doesn't get signals it doesn't
  * want to handle. Thus you cannot kill init even with a SIGKILL even by