libid3tag: Fix reproducibility issue

Configure was swallowing our cflags meaning the resulting binaries were
not reproducible. Tweak configure not to do that and fix reproducibility.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 1395269a)
Signed-off-by: Steve Sakoman <steve@sakoman.com>