[gobject-introspection] meson: fix include dir in .pc files

[Christoph Reiter <creiter src gnome org>]

commit a943f572dd2de0ed8ca438702ad2ba8ef80d7934
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Tue May 19 11:04:09 2020 +0200

    meson: fix include dir in .pc files
    
    See !207

 meson.build | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/meson.build b/meson.build
index f992ad49..a6f3a02e 100644
--- a/meson.build
+++ b/meson.build
@@ -245,6 +245,7 @@ pkg.generate(girepo_lib,
   name : 'gobject-introspection',
   filebase : 'gobject-introspection-1.0',
   description : 'GObject Introspection',
+  subdirs: ['gobject-introspection-1.0'],
   variables : pkgconfig_variables,
   libraries : [glib_dep, gobject_dep],
 )
@@ -260,6 +261,7 @@ pkg.generate(
   name : 'gobject-introspection',
   filebase : 'gobject-introspection-no-export-1.0',
   description : 'GObject Introspection',
+  subdirs: ['gobject-introspection-1.0'],
   variables : pkgconfig_variables,
   libraries : [girepo_lib, glib_dep, gobject_dep],
 )