Tools: add description for SIM_BARO_DRIFT

Author: peterbarker

Tools/autotest/vehicle_test_suite.py

@@ -2331,7 +2331,6 @@ def get_sim_parameter_documentation_get_whitelist(self):
             "SIM_BARO_COUNT",
             "SIM_BARO_DELAY",
             "SIM_BARO_DISABLE",
-            "SIM_BARO_DRIFT",
             "SIM_BARO_FREEZE",
             "SIM_BARO_WCF_BAK",
             "SIM_BARO_WCF_DN",