nmi: Use libpdbg directly

This avoids calling DBus to run a systemd unit that is effectively a
shell script when we already have libpdbg on the system anyway.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: I9a36c38f075d402b9bc406433475a371d1cdbe62
diff --git a/configure.ac b/configure.ac
index ece0591..ce8e755 100644
--- a/configure.ac
+++ b/configure.ac
@@ -45,6 +45,8 @@
     [${srcdir}/gen_makefile.sh ${srcdir} "$myChips" > Makefile.generated],
     [myChips="$CHIPS"])
 
+AC_CHECK_LIB([pdbg], [thread_sreset_all])
+
 PKG_CHECK_MODULES([SYSTEMD], [libsystemd >= 221])
 PKG_CHECK_MODULES([PHOSPHOR_LOGGING], [phosphor-logging])
 PKG_CHECK_MODULES([PHOSPHOR_DBUS_INTERFACES], [phosphor-dbus-interfaces])
@@ -68,5 +70,4 @@
 AC_CONFIG_FILES([Makefile test/Makefile])
 AC_CONFIG_FILES([pcie-poweroff@.service])
 AC_CONFIG_FILES([xyz.openbmc_project.Control.Host.NMI.service])
-AC_CONFIG_FILES([nmi.service])
 AC_OUTPUT