Revert "configure.ac: remove deprecated --with-driver="

This reverts commit 5a478976ae0bb12dd712648d5a9b988dd29c97ef.

It broke the build.  DRI drivers were no longer being installed by
`make install` (and probably not being built at all).  It appears to be
due to a few small, subtle mistakes, and the fix isn't clear enough to
simply commit without going through review.  In the meantime, revert it.
1 file changed