meta-security: handle systemd upgrade

Rename systemd bbappend to work with newer 243.2 version in oe-core.
A wildcard is now used to reduce the need to rename the bbappend on
future upgrades, as the additions it makes have not changed recently.

Bug-AGL: SPEC-2932

Change-Id: Ie6413710e861b8dbf082bcae3d7592f1009927d5
Signed-off-by: Scott Murray <scott.murray@konsulko.com>

diff --git a/meta-security/recipes-core/systemd/systemd_239.bbappend b/meta-security/recipes-core/systemd/systemd_2%.bbappend
similarity index 100%
rename from meta-security/recipes-core/systemd/systemd_239.bbappend
rename to meta-security/recipes-core/systemd/systemd_2%.bbappend