Fix c include

waveshare/include/EPD_7in5_V2.h

@@ -33,6 +33,10 @@
 #ifndef _EPD_7IN5_V2_H_
 #define _EPD_7IN5_V2_H_
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include "DEV_Config.h"
 
 
@@ -46,4 +50,8 @@ void EPD_7IN5_V2_ClearBlack(void);
 void EPD_7IN5_V2_Display(const UBYTE *blackimage);
 void EPD_7IN5_V2_Sleep(void);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif