configure and Makefile are not generated in qemu

Just say it to make
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Makefile

@@ -11,6 +11,11 @@ config-host.mak:
 	@exit 1
 endif
 
+# Don't try to regenerate Makefile or configure
+# We don't generate any of them
+Makefile: ;
+configure: ;
+
 .PHONY: all clean cscope distclean dvi html info install install-doc \
 	recurse-all speed tar tarbin test build-all