ipa: libipa: agc_mean_luminance: Include missing header

agc_mean_luminance.h uses utils::Duration, include the corresponding
header.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>

src/ipa/libipa/agc_mean_luminance.h

@@ -12,6 +12,8 @@
 #include <tuple>
 #include <vector>
 
+#include <libcamera/base/utils.h>
+
 #include <libcamera/controls.h>
 
 #include "libcamera/internal/yaml_parser.h"