staging: vt6656: set all ofdm rates to default

mac80211 rate control decides which odfm rates to use so all of
them should be set enabled at the appropriate bit rate.

This means vnt_get_ofdm_rate is no longer required.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Link: https://lore.kernel.org/r/9a52d7f4-dd3e-efdc-eef8-bb794f7dea6d@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>