Re-disable the setting of 2040/shortgi bits for now.

Re-disable the setting of 2040/shortgi bits for now.

This seems to work fine for STA but not HT/20 AP mode.

Further discussion with net80211 people will need to take place
to ensure that the right flags are set based on the negotiated
capabilities of the remote peer, rather than whatever the local
parameters are.

Sending short-gi frames in 20mhz may work on some chips but
it certainly isn't supported on anything currently supported
by the HAL; and sending HT40 frames in HT20 mode just plain
won't work.