retro-gtk: fix build

srcpkgs/retro-gtk/patches/meson.patch

@@ -0,0 +1,11 @@
+--- a/retro-gtk/meson.build
++++ b/retro-gtk/meson.build
+@@ -189,8 +189,6 @@
+     description: 'A simple GObject game controller library',
+       libraries: retro_gtk_lib,
+            name: 'retro-gtk',
+-      namespace: 'Retro',
+-export_packages: 'retro-gtk',
+        filebase: 'retro-gtk-' + retro_gtk_api_version,
+         version: meson.project_version(),
+         subdirs: 'retro-gtk',