sh64: Fixup the nommu build.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/asm-sh/uaccess_64.h b/include/asm-sh/uaccess_64.h
index f956b7b..a9b68d0 100644
--- a/include/asm-sh/uaccess_64.h
+++ b/include/asm-sh/uaccess_64.h
@@ -274,7 +274,9 @@
 	unsigned long insn, fixup;
 };
 
+#ifdef CONFIG_MMU
 #define ARCH_HAS_SEARCH_EXTABLE
+#endif
 
 /* Returns 0 if exception not found and fixup.unit otherwise.  */
 extern unsigned long search_exception_table(unsigned long addr);