Add a function to allow an external region to be located in TSEG. Select the option to use memory outside of cbmem. Increase the size reserved in TSEG. Change-Id: Ic1073af04475d862753136c9e14e2b2dde31fe66 Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com> Reviewed-on: https://review.coreboot.org/23519 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Aaron Durbin <adurbin@chromium.org>