test: Include specific headers instead of libcamera.h

Let's only pull required headers, to avoid slowing compilation down.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

test/camera/buffer_import.cpp

@@ -12,6 +12,9 @@
 #include <numeric>
 #include <vector>
 
+#include <libcamera/event_dispatcher.h>
+#include <libcamera/timer.h>
+
 #include "libcamera/internal/device_enumerator.h"
 #include "libcamera/internal/media_device.h"
 #include "libcamera/internal/v4l2_videodevice.h"