Hotspot: Set maximun client connections number

This function is for end user to set maximun client
connections number and apply this to hostapd module

Change-Id: I6150b376d22756e8c04ebabe666d81cf3af8fc87

softap/sdk/qsap_api.h

@@ -324,6 +324,7 @@ typedef enum esap_cmd {
     eCMD_GET_AUTO_CHANNEL    = 63,
     eCMD_IEEE80211W          = 64,
     eCMD_WPA_KEY_MGMT        = 65,
+    eCMD_SET_MAX_CLIENTS     = 66,
 
     eCMD_LAST     /** New command numbers should be added above this */
 } esap_cmd_t;