mwifiex: uap: support cfg80211 ignore_broadcast_ssid=2

Firmware already support hidden ssid and keep ssid length,
Open the capability in driver.
Signed-off-by: NXinming Hu <huxm@marvell.com>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/marvell/mwifiex/cfg80211.c

@@ -1979,7 +1979,8 @@ static int mwifiex_cfg80211_start_ap(struct wiphy *wiphy,
 		bss_cfg->bcast_ssid_ctl = 0;
 		break;
 	case NL80211_HIDDEN_SSID_ZERO_CONTENTS:
-		/* firmware doesn't support this type of hidden SSID */
+		bss_cfg->bcast_ssid_ctl = 2;
+		break;
 	default:
 		kfree(bss_cfg);
 		return -EINVAL;