wl12xx: dynamically change fw according to number of active roles

wl12xx uses different fw for single-role and multi-role
scenarios (due to lack of space, some of the fw advanced
features are disabled in the multi-role fw).

Add checks on add_interfae and remove_interface in order
to determine whether a fw switch is needed (and initiate
recovery in this case).

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>