meta-romulus: Change wants to requires for power on services

In order for targets to fail when their services fail,
the relationship must be a "requires"

Change-Id: I9be703179caff8276572c32ecca84209e42448cf
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/meta-romulus/recipes-phosphor/chassis/avsbus-control.bb b/meta-romulus/recipes-phosphor/chassis/avsbus-control.bb
index 20eceda..3c3be27 100644
--- a/meta-romulus/recipes-phosphor/chassis/avsbus-control.bb
+++ b/meta-romulus/recipes-phosphor/chassis/avsbus-control.bb
@@ -28,9 +28,9 @@
 INSTFMT_DIS= "avsbus-disable@{0}.service"
 INSTFMT_WA= "avsbus-workaround@{0}.service"
 TGTFMT = "obmc-power-chassis-on@{0}.target"
-FMT_EN = "../${TMPL_EN}:${TGTFMT}.wants/${INSTFMT_EN}"
-FMT_DIS = "../${TMPL_DIS}:${TGTFMT}.wants/${INSTFMT_DIS}"
-FMT_WA = "../${TMPL_WA}:${TGTFMT}.wants/${INSTFMT_WA}"
+FMT_EN = "../${TMPL_EN}:${TGTFMT}.requires/${INSTFMT_EN}"
+FMT_DIS = "../${TMPL_DIS}:${TGTFMT}.requires/${INSTFMT_DIS}"
+FMT_WA = "../${TMPL_WA}:${TGTFMT}.requires/${INSTFMT_WA}"
 
 SYSTEMD_SERVICE_${PN} += "${TMPL_EN}"
 SYSTEMD_LINK_${PN} += "${@compose_list(d, 'FMT_EN', 'OBMC_CHASSIS_INSTANCES')}"