AP_HAL: board: linux: Add default CAN interface name

libraries/AP_HAL/board/linux.h

@@ -430,3 +430,7 @@
 #ifndef HAL_BOARD_STORAGE_DIRECTORY
 #define HAL_BOARD_STORAGE_DIRECTORY "/var/lib/ardupilot"
 #endif
+
+#ifndef HAL_BOARD_CAN_IFACE_NAME
+#define HAL_BOARD_CAN_IFACE_NAME "can0"
+#endif

libraries/AP_HAL_Linux/CAN.cpp

@@ -68,7 +68,7 @@ bool LinuxCAN::begin(uint32_t bitrate)
 {
     if (_initialized) return _initialized;
     // TODO: Add possibility change bitrate
-    _fd = openSocket("can0");
+    _fd = openSocket(HAL_BOARD_CAN_IFACE_NAME);
     if (_fd > 0) {
         _bitrate = bitrate;
         _initialized = true;