[gegl] add missing cl file

[Øyvind "pippin" Kolås <ok src gnome org>]

commit 07e7bfa6b122544cac3b9201414fd8807cf9c49d
Author: Félix Piédallu <felix piedallu me>
Date:   Wed Aug 21 22:52:22 2019 +0200

    add missing cl file

 opencl/meson.build | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/opencl/meson.build b/opencl/meson.build
index 78a43e30d..52f804784 100644
--- a/opencl/meson.build
+++ b/opencl/meson.build
@@ -6,6 +6,7 @@ opencl_sources = [
   'box-blur.cl',
   'box-max.cl',
   'box-min.cl',
+  'boxblur-1d.cl',
   'brightness-contrast.cl',
   'c2g.cl',
   'checkerboard.cl',