ibexpeak: set HAVE_USBDEBUG_OPTIONS

Previously, I've set this config in mobo config, yet according to
Kyösti Mälkki this parameter is southbridge-specific and not
mobo-specific.

Change-Id: I92428aed5a69d88a371f5d7267bc54ba7530766c
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/4276
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Martin Roth <martin.roth@se-eng.com>

src/southbridge/intel/ibexpeak/Kconfig

@@ -33,6 +33,7 @@ config SOUTH_BRIDGE_OPTIONS # dummy
 	select PCIEXP_COMMON_CLOCK
 	select SPI_FLASH
 	select SOUTHBRIDGE_INTEL_COMMON
+	select HAVE_USBDEBUG_OPTIONS
 
 config EHCI_BAR
 	hex