wlan: Add config param AP LINK MONITOR TIMEOUT

Add AP LINK MONITOR TIMEOUT to change the frequency of KEEP ALIVE
packets sent during the KEEP ALIVE TIMEOUT duration for SAP and GO.
It is used to change the frequency of keep alive packets in the AP
Link Monitor period which is by default 20s. The keep alive packets
are sent as an interval of 3s which can be changed by setting
gApLinkMonitorPeriod in ini file.

CRs-fixed: 425674
Change-Id: I8e632c2e255ac97bb1f06ea7f409d7e5036e7742
diff --git a/CORE/HDD/inc/wlan_hdd_cfg.h b/CORE/HDD/inc/wlan_hdd_cfg.h
index 5defe22..40b5c07 100644
--- a/CORE/HDD/inc/wlan_hdd_cfg.h
+++ b/CORE/HDD/inc/wlan_hdd_cfg.h
@@ -503,6 +503,10 @@
 #define CFG_GO_KEEP_ALIVE_PERIOD_MAX           ( 255)
 #define CFG_GO_KEEP_ALIVE_PERIOD_DEFAULT       ( 20 )
 
+#define CFG_AP_LINK_MONITOR_PERIOD_NAME          "gApLinkMonitorPeriod"
+#define CFG_AP_LINK_MONITOR_PERIOD_MIN           ( 0 )
+#define CFG_AP_LINK_MONITOR_PERIOD_MAX           ( 255)
+#define CFG_AP_LINK_MONITOR_PERIOD_DEFAULT       ( 3 )
 
 #define CFG_BEACON_INTERVAL_NAME               "gBeaconInterval"
 #define CFG_BEACON_INTERVAL_MIN                WNI_CFG_BEACON_INTERVAL_STAMIN
@@ -1751,6 +1755,7 @@
    v_U8_t        enableLTECoex;
    v_U32_t       apKeepAlivePeriod;
    v_U32_t       goKeepAlivePeriod;
+   v_U32_t       apLinkMonitorPeriod;
    v_U32_t       nBeaconInterval;
    v_U8_t        nTxPowerCap;   //In dBm
    v_BOOL_t      fIsLowGainOverride;