wlcore: fix the CONF_TX_AC_ANY_TID to be 0xff

In the enum conf_tx_ac CONF_TX_AC_ANY_TID should
be 0xff to match the firmware's implementation.

Signed-off-by: Yoni Divinsky <yoni.divinsky@ti.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>