tools/include: fix clean and rework COPYING for installed Xen public header

Use actual include directory used to install the public header in
COPYING file.

Also, move the input file out of "tools/include/xen/" because that
directory is removed on `make clean`.

We can't used ./configure because $includedir contain another
variable, so the change is done in Makefile.

Fixes: 4ea75e9a90 ("Rework COPYING installed in /usr/include/xen/, due to several licences")
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

tools/include/.gitignore

@@ -0,0 +1 @@
+/xen/

tools/include/Makefile

@@ -24,6 +24,7 @@ xen-foreign:
 xen-dir:
 	mkdir -p xen/libelf acpi
 	find xen/ acpi/ -type l -exec rm '{}' +
+	sed -e 's#@includedir@#$(includedir)/xen#g' xen.COPYING.in > xen/COPYING
 	ln -s $(XEN_ROOT)/xen/include/public/*.h xen/
 	ln -s $(XEN_ROOT)/xen/include/public/*/ xen/
 	ln -s ../xen-sys/$(XEN_OS) xen/sys

tools/include/xen.COPYING.in

@@ -1,7 +1,7 @@
 XEN NOTICE
 ==========
 
-This licence applies to all files within this subdirectory ("/usr/include/xen")
+This licence applies to all files within this subdirectory ("@includedir@")
 with the exception of "sys/" which may include headers under different
 licences.
 

tools/include/xen/.gitignore

@@ -1,2 +0,0 @@
-*
-!COPYING