wl18xx: disable MCS_13 for wl18xx PG 1.0

There are some problems with MCS_13 in PG 1.0 hardware.  So we disable
it when PG 1.0 is detected.

Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>