staging: vt6656: mac80211 conversion: change vnt_rf_set_txpower

Remove old eScanState code and use.

priv->hw->conf.chandef.chan->hw_value to find current channel

Check hw_value for bounds of vt3226d0_lo_current_table

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>