MN10300: Default config choice GDBSTUB_TTYSM0 should be GDBSTUB_ON_TTYSM0

The configuration choice for the port on which the GDB stub listens has
a default of GDBSTUB_TTYSM0, but this should be GDBSTUB_ON_TTYSM0 to
match the option.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/mn10300/Kconfig.debug b/arch/mn10300/Kconfig.debug
index ff80e86..ce83c74 100644
--- a/arch/mn10300/Kconfig.debug
+++ b/arch/mn10300/Kconfig.debug
@@ -101,7 +101,7 @@
 
 choice
 	prompt "GDB stub port"
-	default GDBSTUB_TTYSM0
+	default GDBSTUB_ON_TTYSM0
 	depends on GDBSTUB
 	help
 	  Select the serial port used for GDB-stub.