Fix "error: 'memset' was not declared in this scope".

Change-Id: I3c08c481e9a315fd374b68142ddedeb2db613c6e
diff --git a/libcamera2/ExynosJpegEncoderForCamera.cpp b/libcamera2/ExynosJpegEncoderForCamera.cpp
index 9eb924f..14d73af 100644
--- a/libcamera2/ExynosJpegEncoderForCamera.cpp
+++ b/libcamera2/ExynosJpegEncoderForCamera.cpp
@@ -17,6 +17,7 @@
 
 #define LOG_TAG "ExynosJpegForCamera"
 #include <utils/Log.h>
+#include <string.h>
 
 #include "ExynosJpegEncoderForCamera.h"