qcacld-3.0: Change keep-alive default to 90s

Currently the default keep-alive interval is 30s. From testing we know
90s works just as well. Change the default keep-alive interval to 90s,
up from 30s, for additional power savings.

Change-Id: If6eda06447a459e2803a4919f46cf1e57c93670f
CRs-Fixed: 2001156

core/hdd/inc/wlan_hdd_cfg.h

@@ -1317,7 +1317,7 @@ typedef enum {
 #define CFG_INFRA_STA_KEEP_ALIVE_PERIOD_NAME          "gStaKeepAlivePeriod"
 #define CFG_INFRA_STA_KEEP_ALIVE_PERIOD_MIN           (0)
 #define CFG_INFRA_STA_KEEP_ALIVE_PERIOD_MAX           (65535)
-#define CFG_INFRA_STA_KEEP_ALIVE_PERIOD_DEFAULT       (30)
+#define CFG_INFRA_STA_KEEP_ALIVE_PERIOD_DEFAULT       (90)
 
 /* WMM configuration */
 #define CFG_QOS_WMM_MODE_NAME                             "WmmIsEnabled"