build: cleanup Makefile.am by moving "data_edit" first

$(data_edit) will be used later at an earlier place in the
makefile (to edit "clients/cloud-setup/nm-cloud-setup.service",
which will be handled earlier). Move it.

Also minor cleanups, like allowing to incrementally build
systemdsystemunit_DATA variable.

Makefile.am

@@ -48,6 +48,7 @@ check_local =
 VAPIGEN_VAPIS =
 dbusservice_DATA =
 dbusactivation_DATA =
+systemdsystemunit_DATA =
 
 INTROSPECTION_GIRS =
 INTROSPECTION_SCANNER_ARGS =
@@ -158,6 +159,24 @@ DISTCLEANFILES += intltool-extract intltool-merge intltool-update
 
 ###############################################################################
 
+data_edit = sed \
+	-e 's|@NM_VERSION[@]|$(NM_VERSION)|g' \
+	-e 's|@bindir[@]|$(bindir)|g' \
+	-e 's|@sbindir[@]|$(sbindir)|g' \
+	-e 's|@sysconfdir[@]|$(sysconfdir)|g' \
+	-e 's|@nmrundir[@]|$(nmrundir)|g' \
+	-e 's|@nmstatedir[@]|$(nmstatedir)|g' \
+	-e 's|@localstatedir[@]|$(localstatedir)|g' \
+	-e 's|@libexecdir[@]|$(libexecdir)|g' \
+	-e 's|@DISTRO_NETWORK_SERVICE[@]|$(DISTRO_NETWORK_SERVICE)|g' \
+	-e 's|@NM_CONFIG_DEFAULT_MAIN_AUTH_POLKIT_TEXT[@]|$(NM_CONFIG_DEFAULT_MAIN_AUTH_POLKIT_TEXT)|g' \
+	-e 's|@NM_CONFIG_DEFAULT_LOGGING_BACKEND_TEXT[@]|$(NM_CONFIG_DEFAULT_LOGGING_BACKEND_TEXT)|g' \
+	-e 's|@NM_CONFIG_DEFAULT_LOGGING_AUDIT_TEXT[@]|$(NM_CONFIG_DEFAULT_LOGGING_AUDIT_TEXT)|g' \
+	-e 's|@NM_CONFIG_DEFAULT_MAIN_RC_MANAGER[@]|$(NM_CONFIG_DEFAULT_MAIN_RC_MANAGER)|g' \
+	-e 's|@NM_CONFIG_DEFAULT_MAIN_DHCP[@]|$(NM_CONFIG_DEFAULT_MAIN_DHCP)|g'
+
+###############################################################################
+
 polkit_policydir = $(datadir)/polkit-1/actions
 
 dist_polkit_policy_in_in_files = \
@@ -4633,28 +4652,13 @@ EXTRA_DIST += \
 # data
 ###############################################################################
 
-data_edit = sed \
-	-e 's|@NM_VERSION[@]|$(NM_VERSION)|g' \
-	-e 's|@bindir[@]|$(bindir)|g' \
-	-e 's|@sbindir[@]|$(sbindir)|g' \
-	-e 's|@sysconfdir[@]|$(sysconfdir)|g' \
-	-e 's|@nmrundir[@]|$(nmrundir)|g' \
-	-e 's|@nmstatedir[@]|$(nmstatedir)|g' \
-	-e 's|@localstatedir[@]|$(localstatedir)|g' \
-	-e 's|@libexecdir[@]|$(libexecdir)|g' \
-	-e 's|@DISTRO_NETWORK_SERVICE[@]|$(DISTRO_NETWORK_SERVICE)|g' \
-	-e 's|@NM_CONFIG_DEFAULT_MAIN_AUTH_POLKIT_TEXT[@]|$(NM_CONFIG_DEFAULT_MAIN_AUTH_POLKIT_TEXT)|g' \
-	-e 's|@NM_CONFIG_DEFAULT_LOGGING_BACKEND_TEXT[@]|$(NM_CONFIG_DEFAULT_LOGGING_BACKEND_TEXT)|g' \
-	-e 's|@NM_CONFIG_DEFAULT_LOGGING_AUDIT_TEXT[@]|$(NM_CONFIG_DEFAULT_LOGGING_AUDIT_TEXT)|g' \
-	-e 's|@NM_CONFIG_DEFAULT_MAIN_RC_MANAGER[@]|$(NM_CONFIG_DEFAULT_MAIN_RC_MANAGER)|g' \
-	-e 's|@NM_CONFIG_DEFAULT_MAIN_DHCP[@]|$(NM_CONFIG_DEFAULT_MAIN_DHCP)|g'
-
 if HAVE_SYSTEMD
 
-systemdsystemunit_DATA = \
+systemdsystemunit_DATA += \
 	data/NetworkManager.service \
 	data/NetworkManager-wait-online.service \
-	data/NetworkManager-dispatcher.service
+	data/NetworkManager-dispatcher.service \
+	$(NULL)
 
 data/NetworkManager.service: $(srcdir)/data/NetworkManager.service.in
 	$(AM_V_GEN) $(data_edit) $< >$@
@@ -4687,21 +4691,23 @@ data/server.conf: $(srcdir)/data/server.conf.in
 	$(AM_V_GEN) $(data_edit) $< >$@
 
 EXTRA_DIST += \
-	data/NetworkManager.service.in \
-	data/NetworkManager-wait-online.service.in \
-	data/NetworkManager-wait-online-systemd-pre200.service.in \
-	data/NetworkManager-dispatcher.service.in \
 	data/84-nm-drivers.rules \
 	data/85-nm-unmanaged.rules \
 	data/90-nm-thunderbolt.rules \
+	data/NetworkManager-dispatcher.service.in \
+	data/NetworkManager-wait-online-systemd-pre200.service.in \
+	data/NetworkManager-wait-online.service.in \
+	data/NetworkManager.service.in \
+	data/meson.build \
 	data/server.conf.in \
-	data/meson.build
+	$(NULL)
 
 CLEANFILES += \
-	data/NetworkManager.service \
-	data/NetworkManager-wait-online.service \
 	data/NetworkManager-dispatcher.service \
-	data/server.conf
+	data/NetworkManager-wait-online.service \
+	data/NetworkManager.service \
+	data/server.conf \
+	$(NULL)
 
 ###############################################################################
 # man