acl: add patch to fix static installation

Just like 'attr', 'acl' doesn't use automake to control the
build/installation of its components, and the static-only installation
process was not installing libacl.a. We add a patch that fixes this.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gustavo Zacarias <gustavo@zacarias.com.ar>