include: unexport registry.h

This file isn't included by any known modules, so no need to keep it
around in the public api.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1348>
(cherry picked from commit 17ad53c803)

hw/xfree86/sdksyms.sh

@@ -270,7 +270,6 @@ cat > sdksyms.c << EOF
 #include "ptrveloc.h"
 #include "region.h"
 #include "regionstr.h"
-#include "registry.h"
 #include "resource.h"
 #include "rgb.h"
 #include "screenint.h"

include/meson.build

@@ -493,7 +493,6 @@ if build_xorg
             'ptrveloc.h',
             'region.h',
             'regionstr.h',
-            'registry.h',
             'resource.h',
             'rgb.h',
             'screenint.h',