[SPARC64]: Move signal compat bits to new header file.

Create asm-sparc64/compat_signal.h and stuff things there.

This avoids the "linux/compat.h includes asm/signal.h but
asm/signal.h needs compat_sigset_t which isn't defined yet"
problems introduced recently.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/sys_sparc32.c b/arch/sparc64/kernel/sys_sparc32.c
index 69444f2..7c6499c 100644
--- a/arch/sparc64/kernel/sys_sparc32.c
+++ b/arch/sparc64/kernel/sys_sparc32.c
@@ -61,6 +61,7 @@
 #include <asm/semaphore.h>
 #include <asm/mmu_context.h>
 #include <asm/a.out.h>
+#include <asm/compat_signal.h>
 
 asmlinkage long sys32_chown16(const char __user * filename, u16 user, u16 group)
 {