carl9170: claim to support IBSS RSN.

On carl9170, HW encryption is disabled on IBSS; the mac80211
software-based encryption is used instead. As mac80211 supports IBSS
RSN (per-STA GTK), claim its support in the carl9170 PHY.
Signed-off-by: Nicolas Cavallari <cavallar@lri.fr>
Acked-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/carl9170/main.c

@@ -1796,6 +1796,9 @@ void *carl9170_alloc(size_t priv_size)
 		ar->noise[i] = -95; /* ATH_DEFAULT_NOISE_FLOOR */
 
 	hw->wiphy->flags &= ~WIPHY_FLAG_PS_ON_BY_DEFAULT;
+
+	/* As IBSS Encryption is software-based, IBSS RSN is supported. */
+	hw->wiphy->flags |= WIPHY_FLAG_IBSS_RSN;
 	return ar;
 
 err_nomem: