sh: Tidy up dependencies for SH-2 build.

SH-2 can presently get in to some pretty bogus states, so
we tidy up the dependencies a bit and get it all building
again.

This gets us a bit closer to a functional allyesconfig
and allmodconfig, though there are still a few things to
fix up.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/Kconfig.debug b/arch/sh/Kconfig.debug
index d849d47..52f6a99 100644
--- a/arch/sh/Kconfig.debug
+++ b/arch/sh/Kconfig.debug
@@ -86,6 +86,7 @@
 	bool "Include KGDB kernel debugger"
 	select FRAME_POINTER
 	select DEBUG_INFO
+	depends on CPU_SH3 || CPU_SH4
 	help
 	  Include in-kernel hooks for kgdb, the Linux kernel source level
 	  debugger.  See <http://kgdb.sourceforge.net/> for more information.