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/mapped-buffer.cpp

@@ -7,6 +7,8 @@
 
 #include <iostream>
 
+#include <libcamera/framebuffer_allocator.h>
+
 #include "libcamera/internal/buffer.h"
 
 #include "camera_test.h"