xtensa: nommu support

Add support for !CONFIG_MMU setups.

Signed-off-by: Johannes Weiner <jw@emlix.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index a51d36a..80d24c4 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -1463,6 +1463,7 @@
 	callx0	a0		# should not return
 1:	j	1b
 
+#ifdef CONFIG_MMU
 /*
  * We should never get here. Bail out!
  */
@@ -1775,7 +1776,7 @@
 	bbsi.l	a2, PS_UM_BIT, 1f
 	j	_kernel_exception
 1:	j	_user_exception
-
+#endif /* CONFIG_MMU */
 
 /*
  * System Calls.