wlcore: configure the remote rates with our own rates

With the new connection flow, start_sta is called before
the remote rates where updated. Use our own supported rates
instead to make sure we don't disable any potential rate
(the rate policies will be updated later, but there is
currently no way to update the remote rates)

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