softap: sdk: Add 'vendor.' prefix to wlan.driver.config

* In https://github.com/LineageOS/android_hardware_qcom_wlan/commit/126af66b042373c3cfa5bee2d6c2cf2fb620e7fe,
  the prop wlan.driver.config was renamed to vendor.wlan.driver.config.
  Therefore, make the same change on softap as well.

Change-Id: I696d851c8ecd35ec42cf680149c402b3b8044cfc

softap/sdk/qsap_api.c

@@ -3439,7 +3439,7 @@ void check_for_configuration_files(void)
 
 void qsap_set_ini_filename(void)
 {
-    if (property_get("wlan.driver.config", ini_file, NULL)) {
+    if (property_get("vendor.wlan.driver.config", ini_file, NULL)) {
         fIni = ini_file;
         ALOGE("INI FILE PROP PRESENT %s\n", fIni);
     } else