Disable the GDB stub by default

I would prefer to see the exception dump on serial rather than cryptic
GDB protocol.

Change-Id: Ib25513d33e6a31da24586fecb00adb5206bb43bd
Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Reviewed-on: http://review.coreboot.org/811
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
Tested-by: build bot (Jenkins)
diff --git a/src/Kconfig b/src/Kconfig
index c165d93..845d26f 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -570,7 +570,7 @@
 # TODO: Better help text and detailed instructions.
 config GDB_STUB
 	bool "GDB debugging support"
-	default y
+	default n
 	help
 	  If enabled, you will be able to set breakpoints for gdb debugging.
 	  See src/arch/x86/lib/c_start.S for details.