sparc64: fix sparse "Should it be static?" warnings in signal32.c

Fix following warnings:
signal32.c:140:6: warning: symbol 'do_sigreturn32' was not declared. Should it be static?
signal32.c:230:17: warning: symbol 'do_rt_sigreturn32' was not declared. Should it be static?
signal32.c:729:6: warning: symbol 'do_signal32' was not declared. Should it be static?
signal32.c:773:16: warning: symbol 'do_sys32_sigstack' was not declared. Should it be static?

Add proper prototypes and drop local prototype
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/kernel/kernel.h

@@ -44,6 +44,12 @@ void __irq_entry smp_receive_signal_client(int irq, struct pt_regs *regs);
 /* pci.c */
 int pci64_dma_supported(struct pci_dev *pdev, u64 device_mask);
 
+/* signal32.c */
+void do_sigreturn32(struct pt_regs *regs);
+asmlinkage void do_rt_sigreturn32(struct pt_regs *regs);
+void do_signal32(struct pt_regs * regs);
+asmlinkage int do_sys32_sigstack(u32 u_ssptr, u32 u_ossptr, unsigned long sp);
+
 #endif
 
 #ifdef CONFIG_SPARC32

arch/sparc/kernel/signal32.c

@@ -31,6 +31,7 @@
 #include <asm/switch_to.h>
 
 #include "sigutil.h"
+#include "kernel.h"
 
 /* This magic should be in g_upper[0] for all upper parts
  * to be valid.

arch/sparc/kernel/signal_64.c

@@ -35,9 +35,10 @@
 #include <asm/switch_to.h>
 #include <asm/cacheflush.h>
 
-#include "entry.h"
-#include "systbls.h"
 #include "sigutil.h"
+#include "systbls.h"
+#include "kernel.h"
+#include "entry.h"
 
 /* {set, get}context() needed for 64-bit SparcLinux userland. */
 asmlinkage void sparc64_set_context(struct pt_regs *regs)
@@ -492,7 +493,6 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 
 #ifdef CONFIG_COMPAT
 	if (test_thread_flag(TIF_32BIT)) {
-		extern void do_signal32(struct pt_regs *);
 		do_signal32(regs);
 		return;
 	}