build: move glib marshaller/enum generation to src dir

the build/ dir is getting gutted so this commit moves
the two still needed bits to the source dir.

build/autotools/Makefile.am

@@ -1,8 +1,6 @@
 NULL =
 
 EXTRA_DIST = \
-	Makefile.am.marshal	\
-	Makefile.am.enums	\
 	introspection.m4	\
 	gtk-doc.m4		\
 	as-compiler-flag.m4	\

clutter/Makefile.am

@@ -542,13 +542,13 @@ cally_include_HEADERS = $(cally_sources_h)
 # glib-genmarshal rules
 glib_marshal_list = clutter-marshal.list
 glib_marshal_prefix = _clutter_marshal
-include $(top_srcdir)/build/autotools/Makefile.am.marshal
+include $(srcdir)/Makefile.am.marshal
 
 # glib-mkenums rules
 glib_enum_h = clutter-enum-types.h
 glib_enum_c = clutter-enum-types.c
 glib_enum_headers = $(source_h) $(deprecated_h)
-include $(top_srcdir)/build/autotools/Makefile.am.enums
+include $(srcdir)/Makefile.am.enums
 
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = $(pc_files)
@@ -674,4 +674,8 @@ gir_DATA = $(INTROSPECTION_GIRS)
 typelibdir = $(mutterlibdir)
 typelib_DATA = $(INTROSPECTION_GIRS:.gir=.typelib)
 
+EXTRA_DIST += \
+	Makefile.am.marshal	\
+	Makefile.am.enums
+
 CLEANFILES += $(gir_DATA) $(typelib_DATA)