libsdl-ttf: Update configure.patch

Update configure.patch to modernise configure.in, in particular passing the
foreign option to automake. The other changes are other modernisations
that were needed to make that.

Also use rm -f so that do_configure can rerun in the prepend.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>