When user space use "iw dev" to get tx power info, driver send WMI_REQUEST_STATS_CMDID to fw, fw update tx power info with two events, usually we parse the last event, and maybe get invalid value. Filter invalid value for each event, and get valid tx power value from the mac which the AP/STA mode work. Change-Id: I2411bb87e03fe385759852b028819e19a055b7f3 CRs-Fixed: 3474361