Fix host-error-monitor recipe to build in Yocto

A recent update to build outside of Yocto required the flag to
build in Yocto, so set the flag.  Also remove a CFLAG that is
not needed.

Tested:
Built in Yocto.

Change-Id: I4e466bd4f7a6485365291b85405b22477486bf8c
Signed-off-by: Jason M. Bills <jason.m.bills@linux.intel.com>
diff --git a/meta-common/recipes-core/host-error-monitor/host-error-monitor_git.bb b/meta-common/recipes-core/host-error-monitor/host-error-monitor_git.bb
index fb0f412..d03fa0a 100644
--- a/meta-common/recipes-core/host-error-monitor/host-error-monitor_git.bb
+++ b/meta-common/recipes-core/host-error-monitor/host-error-monitor_git.bb
@@ -12,4 +12,5 @@
 S = "${WORKDIR}/git"
 
 SYSTEMD_SERVICE_${PN} += "xyz.openbmc_project.HostErrorMonitor.service"
-SECURITY_CFLAGS_pn-host-error-monitor  = "${SECURITY_NOPIE_CFLAGS}"
+
+EXTRA_OECMAKE = "-DYOCTO=1"