Add the missing license description.

hanliutong · hanliutong · commit 515b4a268967 · 2024-10-25T11:37:07.000Z
diff --git a/3rdparty/hal_rvv/hal_rvv_1p0/merge.hpp b/3rdparty/hal_rvv/hal_rvv_1p0/merge.hpp
@@ -1,3 +1,6 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
 #ifndef OPENCV_HAL_RVV_MERGE_HPP_INCLUDED
 #define OPENCV_HAL_RVV_MERGE_HPP_INCLUDED
 
