Update LoRaMac-node to Version 4.4.4，fix Security breach found by Tencent Blade Team please refer to security advisory - CVE-2020-11068

fix Security breach found by Tencent Blade Team please refer to security advisory - CVE-2020-11068

components/connectivity/LoraWAN/system/spi.h

@@ -23,6 +23,11 @@
 #ifndef __SPI_H__
 #define __SPI_H__
 
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
 #include "gpio.h"
 
 /*!
@@ -97,4 +102,8 @@ void SpiFrequency( Spi_t *obj, uint32_t hz );
  */
 uint16_t SpiInOut( Spi_t *obj, uint16_t outData );
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif // __SPI_H__