sh: Disable 4KSTACKS on nommu.

4k stacks on nommu ends up blowing up with all sorts of interesting
slab corruption. Disable this by default unless BROKEN is also
enabled.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/Kconfig.debug b/arch/sh/Kconfig.debug
index 0d2ef1e..0f45498 100644
--- a/arch/sh/Kconfig.debug
+++ b/arch/sh/Kconfig.debug
@@ -81,7 +81,7 @@
 
 config 4KSTACKS
 	bool "Use 4Kb for kernel stacks instead of 8Kb"
-	depends on DEBUG_KERNEL
+	depends on DEBUG_KERNEL && (MMU || BROKEN)
 	help
 	  If you say Y here the kernel will use a 4Kb stacksize for the
 	  kernel stack attached to each process/thread. This facilitates