mac80211: remove hw.conf.channel usage where possible

Removes hw.conf.channel usage from the following functions:
 * ieee80211_mandatory_rates
 * ieee80211_sta_get_rates
 * ieee80211_frame_duration
 * ieee80211_rts_duration
 * ieee80211_ctstoself_duration

This is in preparation for multi-channel operation.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/b43legacy/main.c

@@ -1056,6 +1056,7 @@ static void b43legacy_write_probe_resp_plcp(struct b43legacy_wldev *dev,
 	b43legacy_generate_plcp_hdr(&plcp, size + FCS_LEN, rate->hw_value);
 	dur = ieee80211_generic_frame_duration(dev->wl->hw,
 					       dev->wl->vif,
+					       IEEE80211_BAND_2GHZ,
 					       size,
 					       rate);
 	/* Write PLCP in two parts and timing for packet transfer */
@@ -1121,6 +1122,7 @@ static const u8 *b43legacy_generate_probe_resp(struct b43legacy_wldev *dev,
 					 IEEE80211_STYPE_PROBE_RESP);
 	dur = ieee80211_generic_frame_duration(dev->wl->hw,
 					       dev->wl->vif,
+					       IEEE80211_BAND_2GHZ,
 					       *dest_size,
 					       rate);
 	hdr->duration_id = dur;

drivers/net/wireless/b43legacy/xmit.c

@@ -228,6 +228,7 @@ static int generate_txhdr_fw3(struct b43legacy_wldev *dev,
 	} else {
 		txhdr->dur_fb = ieee80211_generic_frame_duration(dev->wl->hw,
 							 info->control.vif,
+							 info->band,
 							 fragment_len,
 							 rate_fb);
 	}