Add C extern to support C++

lib/drivers/include/kpu.h

@@ -19,6 +19,10 @@
 #include <stdint.h>
 #include "dmac.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define kpu_matmul_begin kpu_conv2d_output
 
 typedef int (*plic_irq_callback_t)(void *ctx);
@@ -959,4 +963,8 @@ int kpu_get_output(kpu_model_context_t *ctx, uint32_t index, uint8_t **data, siz
  */
 int kpu_run_kmodel(kpu_model_context_t *ctx, const uint8_t *src, dmac_channel_number_t dma_ch, kpu_done_callback_t done_callback, void *userdata);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif