Make header structure compatible with simulator

Currently, the generated Makefile doesn't successfully compile. But it
is possible to run the simulator again by manually editing the Makefile.

Core/Src/vehicle.c

@@ -2,6 +2,7 @@
 
 #include "main.h"
 #include "ui.h"
+#include "vehicle_state.h"
 
 #include "can-halal.h"
 
@@ -32,8 +33,6 @@
 #define CAN_CS_INTERNAL_TEMP_FACTOR 0.01
 #define CAN_ABX_MISC_DISTANCE_TOTAL_FACTOR 0.01
 
-VehicleState vehicle_state = {0};
-
 void vehicle_thread_entry(ULONG hfdcan_addr) {
   memset(&vehicle_state, 0, sizeof(vehicle_state));
   ftcan_init((void *)hfdcan_addr);