meson: install a pkgconfig file for libwireplumber

lib/wp/meson.build

@@ -83,3 +83,8 @@ wp_dep = declare_dependency(
   include_directories: wp_lib_include_dir,
   dependencies: [gobject_dep]
 )
+
+pkgconfig.generate(wp_lib,
+  libraries: [gobject_dep, gio_dep],
+  subdirs: 'wireplumber-' + wireplumber_api_version
+)

meson.build

@@ -34,6 +34,7 @@ gio_dep = dependency('gio-2.0')
 pipewire_dep = dependency('libpipewire-0.3')
 
 gnome = import('gnome')
+pkgconfig = import('pkgconfig')
 
 wp_lib_include_dir = include_directories('lib')