build: cleanup configure detritus at toplevel and stubdom

These files were left over after
	$ git clean -f -dx
	$ ./configure
	$ make distclean
and picked up by a subsequent.
        $ git clean -f -dx

Ensure that these files are also correctly ignored.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>

Makefile

@@ -167,6 +167,7 @@ endif
 	rm -rf dist patches/tmp
 	for i in $(ALLKERNELS) ; do $(MAKE) $$i-delete ; done
 	rm -rf patches/*/.makedep
+	rm -rf config.log config.status config.cache autom4te.cache
 
 # Linux name for GNU distclean
 .PHONY: mrproper