wl18xx: support MIMO only if HT mode is not forced to SISO

Don't use MIMO rates when HT mode is forced to SISO, even if we have
multiple antennas.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
1 file changed