hw_feature: Correctly select mode in case of the 6 GHz band

hw_feature: Correctly select mode in case of the 6 GHz band

There are 2 HW modes with IEEE80211_MODE_A: one for the 5 GHz channels
and one for 6 GHz channels. Since hw_get_chan() checks all the
compatible hw modes, eventually, an incorrect hw mode is selected.

To fix this, add a function that checks if a specific mode supports
the requested frequency and if so use it as the current mode.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>