wlcore: reconfigure rate policy on association

When first configuring the rate policy, before auth,
we still don't have the correct rates that were
agreed during association.

Reconfigure the rate policy on association in order
to update them.

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