The linux kernel will unconditionally route all USB ports to the XCHI controller at boot. The EHCI controller can then be disabled, and it should be left disabled by the reference code when this is done. However not all OS may do this unconditional route, so provide an option to the reference code binary to enable this behavior. Change-Id: Iedf5af54182bf109cd1119c1999e46300665d41e Signed-off-by: Duncan Laurie <dlaurie@chromium.org> Reviewed-on: https://gerrit.chromium.org/gerrit/63797 Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: http://review.coreboot.org/4403 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>