cfg80211: disable 5/10 MHz support for all drivers

Due to nl80211 API breakage, 5/10 MHz support is broken for
all drivers. Fixing it requires adding new API, but that
can't be done as a bugfix commit since that would require
either updating all APIs in the trees needing the bugfix or
cause different kernels to have incompatible API.

Therefore, just disable 5/10 MHz support for all drivers.

Cc: stable@vger.kernel.org [3.12]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/core.c

@@ -451,6 +451,9 @@ int wiphy_register(struct wiphy *wiphy)
 	int i;
 	u16 ifmodes = wiphy->interface_modes;
 
+	/* support for 5/10 MHz is broken due to nl80211 API mess - disable */
+	wiphy->flags &= ~WIPHY_FLAG_SUPPORTS_5_10_MHZ;
+
 #ifdef CONFIG_PM
 	if (WARN_ON(wiphy->wowlan &&
 		    (wiphy->wowlan->flags & WIPHY_WOWLAN_GTK_REKEY_FAILURE) &&