meta-witherspoon: Fix missing power-supply-monitor configs

The power-supply-monitor configs were installed by
SYSTEMD_ENVIRONMENT_FILE_${PN}, which is defined in
obmc-phosphor-systemd.bbclass.

phosphor-power recipe does not inherit obmc-phosphor-systemd, results in
the files installed by SYSTEMD_ENVIRONMENT_FILE_${PN} are not installed
at all.

Fix this issue by inherit obmc-phosphor-systemd in the bbappend.

Tested: Verify the witherspoon build includes the power-supply-monitor
        configs.

(From meta-ibm rev: d4374bf93e5927ccadb9de954384096ffb8590ec)

Change-Id: Iaa3a04694c7b591d349a32529a0afef16239203d
Signed-off-by: Lei YU <mine260309@gmail.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-ibm/meta-witherspoon/recipes-phosphor/power/phosphor-power_%.bbappend b/meta-ibm/meta-witherspoon/recipes-phosphor/power/phosphor-power_%.bbappend
index b90dc9b..350c996 100644
--- a/meta-ibm/meta-witherspoon/recipes-phosphor/power/phosphor-power_%.bbappend
+++ b/meta-ibm/meta-witherspoon/recipes-phosphor/power/phosphor-power_%.bbappend
@@ -1,5 +1,7 @@
 FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
 
+inherit obmc-phosphor-systemd
+
 SRC_URI += "file://psu.json"
 
 EXTRA_OEMESON += "-Ducd90160-yaml=${STAGING_DIR_HOST}${datadir}/power-sequencer/ucd90160.yaml"
@@ -12,4 +14,4 @@
 FILES_${PN} += "${datadir}/phosphor-power/psu.json"
 
 PSU_MONITOR_ENV_FMT = "obmc/power-supply-monitor/power-supply-monitor-{0}.conf"
-SYSTEMD_ENVIRONMENT_FILE_${PN} += "${@compose_list(d, 'PSU_MONITOR_ENV_FMT', 'OBMC_POWER_SUPPLY_INSTANCES')}"
+SYSTEMD_ENVIRONMENT_FILE_${PN}_append_ibm-ac-server += "${@compose_list(d, 'PSU_MONITOR_ENV_FMT', 'OBMC_POWER_SUPPLY_INSTANCES')}"