Ford: handle metric cruise speed (v2)

**Description**

I found a signal which appears to match the IPC "Show km/h" setting.
Requires https://github.com/commaai/opendbc/pull/1010.

**Verification**

- [ ] Test in car and confirm that toggling the "Show km/h" setting does
  not result in the cruise speed shown in openpilot being incorrect.
- [ ] Test in a non-English (metric) car.

selfdrive/car/ford/carstate.py

@@ -57,7 +57,8 @@ class CarState(CarStateBase):
       ret.steerFaultTemporary |= cp.vl["Lane_Assist_Data3_FD1"]["LatCtlSte_D_Stat"] not in (1, 2, 3)
 
     # cruise state
-    ret.cruiseState.speed = cp.vl["EngBrakeData"]["Veh_V_DsplyCcSet"] * CV.MPH_TO_MS
+    is_metric = cp.vl["INSTRUMENT_PANEL"]["METRIC_UNITS"] == 1
+    ret.cruiseState.speed = cp.vl["EngBrakeData"]["Veh_V_DsplyCcSet"] * (CV.KPH_TO_MS if is_metric else CV.MPH_TO_MS)
     ret.cruiseState.enabled = cp.vl["EngBrakeData"]["CcStat_D_Actl"] in (4, 5)
     ret.cruiseState.available = cp.vl["EngBrakeData"]["CcStat_D_Actl"] in (3, 4, 5)
     ret.cruiseState.nonAdaptive = cp.vl["Cluster_Info1_FD1"]["AccEnbl_B_RqDrv"] == 0
@@ -120,6 +121,7 @@ class CarState(CarStateBase):
       ("BrakeSnData_4", 50),
       ("EngBrakeData", 10),
       ("Cluster_Info1_FD1", 10),
+      ("INSTRUMENT_PANEL", 10),
       ("SteeringPinion_Data", 100),
       ("EPAS_INFO", 50),
       ("Steering_Data_FD1", 10),