cfg80211: make ethtool the driver's responsibility

Currently, cfg80211 tries to implement ethtool, but that doesn't
really scale well, with all the different operations. Make the
lower-level driver responsible for it, which currently only has
an effect on mac80211. It will similarly not scale well at that
level though, since mac80211 also has many drivers.

To cleanly implement this in mac80211, introduce a new file and
move some code to appropriate places.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/core.c

@@ -25,7 +25,6 @@
 #include "sysfs.h"
 #include "debugfs.h"
 #include "wext-compat.h"
-#include "ethtool.h"
 #include "rdev-ops.h"
 
 /* name for sysfs, %d is appended */
@@ -927,8 +926,6 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb,
 		/* allow mac80211 to determine the timeout */
 		wdev->ps_timeout = -1;
 
-		netdev_set_default_ethtool_ops(dev, &cfg80211_ethtool_ops);
-
 		if ((wdev->iftype == NL80211_IFTYPE_STATION ||
 		     wdev->iftype == NL80211_IFTYPE_P2P_CLIENT ||
 		     wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr)