qcacld-3.0: Do not use NULL data packet for BSS max idle

Do not use the NULL data keep alive method if BSS max idle period
is advertised as NULL packet is not encrypted.
Set the keep alive data method to management if BSS max idle period
is set.

Change-Id: Ib30e8a426e18fe3564fc2de8d48e85fb53840718
CRs-Fixed: 3007868

core/wma/src/wma_mgmt.c

@@ -817,8 +817,11 @@ void wma_set_sta_keep_alive(tp_wma_handle wma, uint8_t vdev_id,
 	params.method = method;
 	params.timeperiod = timeperiod;
 	if (intr) {
-		if (intr->bss_max_idle_period)
+		if (intr->bss_max_idle_period) {
 			params.timeperiod = intr->bss_max_idle_period;
+			if (method == WMI_KEEP_ALIVE_NULL_PKT)
+				params.method = WMI_KEEP_ALIVE_MGMT_FRAME;
+		}
 	}
 
 	if (hostv4addr)