ath9k: Enable DFS only when ATH9K_DFS_CERTIFIED

Add DFS interface combination only when
CONFIG_ATH9K_DFS_CERTIFIED is set. In other case
user can run CAC/beaconing without proper handling
of pulse events (without radar detection activated).
Reported-by: NCedric Voncken <cedric.voncken@acksys.fr>
Signed-off-by: NJanusz Dziedzic <janusz.dziedzic@tieto.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/init.c

@@ -670,6 +670,7 @@ static const struct ieee80211_iface_combination if_comb[] = {
 		.num_different_channels = 1,
 		.beacon_int_infra_match = true,
 	},
+#ifdef CONFIG_ATH9K_DFS_CERTIFIED
 	{
 		.limits = if_dfs_limits,
 		.n_limits = ARRAY_SIZE(if_dfs_limits),
@@ -679,6 +680,7 @@ static const struct ieee80211_iface_combination if_comb[] = {
 		.radar_detect_widths =	BIT(NL80211_CHAN_WIDTH_20_NOHT) |
 					BIT(NL80211_CHAN_WIDTH_20),
 	}
+#endif
 };
 
 static void ath9k_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw)