cfg80211: drop duplicated documentation of field "probe_resp_offload"

The field "probe_resp_offload" was already documented above the
definition of struct wiphy. Both comments were identical.
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200221115604.594035-1-Jerome.Pouiller@silabs.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -4666,11 +4666,6 @@ struct wiphy {
 	u32 available_antennas_tx;
 	u32 available_antennas_rx;
 
-	/*
-	 * Bitmap of supported protocols for probe response offloading
-	 * see &enum nl80211_probe_resp_offload_support_attr. Only valid
-	 * when the wiphy flag @WIPHY_FLAG_AP_PROBE_RESP_OFFLOAD is set.
-	 */
 	u32 probe_resp_offload;
 
 	const u8 *extended_capabilities, *extended_capabilities_mask;