sb/intel/common: Properly guard USB debug

The declarations in usb_debug.c needs to be guarded in order to not
conflict with other chipsets.

Change-Id: I84c3401b9419f2878c2cfdf81147fa854018f9ae
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36878
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Mike Banon <mikebdp2@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/southbridge/intel/common/Kconfig b/src/southbridge/intel/common/Kconfig
index 57c0dbe..18bcd2e 100644
--- a/src/southbridge/intel/common/Kconfig
+++ b/src/southbridge/intel/common/Kconfig
@@ -46,6 +46,10 @@
 config SOUTHBRIDGE_INTEL_COMMON_FINALIZE
 	bool
 
+config SOUTHBRIDGE_INTEL_COMMON_USB_DEBUG
+	def_bool n
+	select HAVE_USBDEBUG
+
 config INTEL_DESCRIPTOR_MODE_CAPABLE
 	def_bool n
 	help