sh: Make 29/32-bit mode check helper generally available.

Presently __in_29bit_mode() is only defined for the PMB case, but
it's also easily derived from the CONFIG_29BIT and CONFIG_32BIT &&
CONFIG_PMB=n cases.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/include/asm/mmu.h b/arch/sh/include/asm/mmu.h
index e5e8f48..ca7d91e 100644
--- a/arch/sh/include/asm/mmu.h
+++ b/arch/sh/include/asm/mmu.h
@@ -31,6 +31,7 @@
 
 #ifndef __ASSEMBLY__
 #include <linux/errno.h>
+#include <linux/threads.h>
 
 /* Default "unsigned long" context */
 typedef unsigned long mm_context_id_t[NR_CPUS];
@@ -72,6 +73,7 @@
 	       unsigned long size, unsigned long flags);
 void pmb_unmap(unsigned long addr);
 int pmb_init(void);
+bool __in_29bit_mode(void);
 #else
 static inline long pmb_remap(unsigned long virt, unsigned long phys,
 			     unsigned long size, unsigned long flags)
@@ -87,8 +89,14 @@
 {
 	return -ENODEV;
 }
-#endif /* CONFIG_PMB */
 
+#ifdef CONFIG_29BIT
+#define __in_29bit_mode()	(1)
+#else
+#define __in_29bit_mode()	(0)
+#endif
+
+#endif /* CONFIG_PMB */
 #endif /* __ASSEMBLY__ */
 
 #endif /* __MMU_H */