buildroot

Revert "automake: complete the removal of the target package"

This reverts commit 6c33512e01acfc576dc4e3ad28def8b29c0db822.

We DO need to look in the staging directory for .m4 files installed by other
target packages, otherwise we'll have breakage like:

http://autobuild.buildroot.net/results/b20/b20e3efcb0be3032781d7b2f0ef4c351834da0ce/

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>