meson: switch code dependency to libsystemd

For a while now systemd has packaged a separate `libsystemd`.  For
meson dependency, `systemd` should be used when looking for systemd
service file paths and `libsystemd` should be used for `sd_*` functions.

Update the dependency accordingly.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I9768dd66c4180085f201a0b77385d696bdd1680f
diff --git a/softoff/meson.build b/softoff/meson.build
index cdc5d03..1d52b8e 100644
--- a/softoff/meson.build
+++ b/softoff/meson.build
@@ -1,12 +1,12 @@
 softpower_pre = [
+  boost,
   ipmid_dep,
-  phosphor_logging_dep,
+  libsystemd_dep,
   phosphor_dbus_interfaces_dep,
-  sdeventplus_dep,
+  phosphor_logging_dep,
   sdbusplus_dep,
-  systemd,
+  sdeventplus_dep,
   softoff_dbus,
-  boost
 ]
 
 softpower_lib = static_library(