Not all ports have retimers. Add a property to denote that a particular port has a retimer (instead of assuming that all ports have retimers). BUG=b:263964979 TEST=Verified on guybrush; SSDT shows retimer-switch on port1 when device tree is updated accordingly. Change-Id: I754323236d2912777b63cede0fce2ccf7882cfea Signed-off-by: Prashant Malani <pmalani@chromium.org> Reviewed-on: https://review.coreboot.org/c/coreboot/+/71663 Reviewed-by: Robert Zieba <robertzieba@google.com> Reviewed-by: Caveh Jalali <caveh@chromium.org> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>