rsync: make acl support non-random

If acl is selected then add it to dependencies so it can be used by
rsync in a predictable fashion.
Extended attributes are handled directly via linux, there's no need
for the xattr package/library.

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