Update modbus.c

Author: ant32

src/libmodbus/modbus.c

@@ -19,7 +19,6 @@
 #include <unistd.h>
 #endif
 #ifdef ARDUINO
-#include <Arduino.h>
 
 #ifndef DEBUG
 #define printf(...) {}
@@ -51,6 +50,11 @@
 #define ENOTSUP 134
 #endif
 
+/* workaround for stm32duino delay and delayMicroseconds */
+#ifdef ARDUINO_ARCH_STM32
+#include <wiring_time.h>
+#endif
+
 #include "modbus.h"
 #include "modbus-private.h"