system/qcom:Use wlan config path from android property wlan.driver.config

wlan.driver.config android property points to the correct wlan driver
config file. This config file is used to get/set config items related to
wlan driver as indicated from userspace through Qualcomm SoftAP SDK
commands.

Change-Id: I82efd922c72a77b281f007ba95db7042f5ac5e82
CRs-fixed: 315065

softap/sdk/qsap_api.h

@@ -535,6 +535,7 @@ int qsapsetSoftap(int argc, char *argv[]);
 void qsap_del_ctrl_iface(void);
 s16 wifi_qsap_reset_to_default(s8 *pcfgfile, s8 *pdefault);
 void check_for_configuration_files(void);
+void qsap_set_ini_filename(void);
 
 #if __cplusplus
 };  // extern "C"