src/poky:systemd: Remove /var/log/README using a patch

Commit f82d9c997ba (systemd: enable create-log-dirs) removed the
creation of the /var/log/README symbolic link by using sed. However, the
update to 257 changed the target line and the sed expression no longer
matches. Rather than correcting the sed expression, use a patch to
remove /var/log/README so that any future changes do not go unnoticed.

(From OE-Core rev: 76cf5994262f9fd76cf27e111eb67ad1645541f1)

Signed-off-by: Peter Kjellerstedt <peter.kjellerstedtaxis.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briandbootlin.com>
Signed-off-by: Ross Burton <ross.burtonarm.com>

Author: Peter Kjellerstedt