ath9k: add a missing case statement to ath_ant_div_comb_alt_check

The 'ar9003_hw_antdiv_comb_conf_get' function sets div_group to 2
however that value is not used in 'ath_ant_div_comb_alt_check'.
Signed-off-by: NGabor Juhos <juhosg@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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

@@ -39,6 +39,7 @@ static inline bool ath_ant_div_comb_alt_check(u8 div_group, int alt_ratio,
 			result = true;
 		break;
 	case 1:
+	case 2:
 		if ((((curr_main_set == ATH_ANT_DIV_COMB_LNA2) &&
 			(curr_alt_set == ATH_ANT_DIV_COMB_LNA1) &&
 				(alt_rssi_avg >= (main_rssi_avg - 5))) ||