wl18xx: support PG2 version of the chip

PG2 has a unique chip id. It supports similar HW quirks.

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