mac80211: add unified BSS configuration

This patch (based on Ron Rindjunsky's) creates a framework for
a unified way to pass BSS configuration to drivers that require
the information, e.g. for implementing power save mode.

This patch introduces new ieee80211_bss_conf structure that is
passed to the driver via the new bss_info_changed() callback
when the BSS configuration changes.

This new BSS configuration infrastructure adds the following
new features:
 * drivers are notified of their association AID
 * drivers are notified of association status

and replaces the erp_ie_changed() callback. The patch also does
the relevant driver updates for the latter change.

Signed-off-by: Ron Rindjunsky <ron.rindjunsky@intel.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2500usb.c b/drivers/net/wireless/rt2x00/rt2500usb.c
index 6579718..1933113 100644
--- a/drivers/net/wireless/rt2x00/rt2500usb.c
+++ b/drivers/net/wireless/rt2x00/rt2500usb.c
@@ -1776,7 +1776,7 @@
 	.config_interface	= rt2x00mac_config_interface,
 	.configure_filter	= rt2500usb_configure_filter,
 	.get_stats		= rt2x00mac_get_stats,
-	.erp_ie_changed		= rt2x00mac_erp_ie_changed,
+	.bss_info_changed	= rt2x00mac_bss_info_changed,
 	.conf_tx		= rt2x00mac_conf_tx,
 	.get_tx_stats		= rt2x00mac_get_tx_stats,
 	.beacon_update		= rt2500usb_beacon_update,