systemd-conf: configure wired network with dhcp

Add a configure file for systemd.networkd to configure wired network
interfaces with dhcp. It works with common network interfaces such eth0
and eno1. And do not install it for qemu bsps.

Refer to
https://github.com/YoeDistro/meta-yoe/tree/master/recipes-core/systemd

[YOCTO #13057]

(From OE-Core rev: d87efd14ce0471135c0aa7fd7b5da2808acb9c76)

Signed-off-by: Kai Kang <kai.kang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/systemd/systemd-conf/wired.network

@@ -0,0 +1,9 @@
+[Match]
+Name=en* eth*
+
+[Network]
+DHCP=yes
+
+[DHCP]
+RouteMetric=10
+ClientIdentifier=mac

meta/recipes-core/systemd/systemd-conf_242.bb

@@ -10,17 +10,22 @@ SRC_URI = "\
     file://logind.conf \
     file://system.conf \
     file://system.conf-qemuall \
+    file://wired.network \
 "
 
 do_install() {
 	install -D -m0644 ${WORKDIR}/journald.conf ${D}${systemd_unitdir}/journald.conf.d/00-${PN}.conf
 	install -D -m0644 ${WORKDIR}/logind.conf ${D}${systemd_unitdir}/logind.conf.d/00-${PN}.conf
 	install -D -m0644 ${WORKDIR}/system.conf ${D}${systemd_unitdir}/system.conf.d/00-${PN}.conf
+	install -D -m0644 ${WORKDIR}/wired.network ${D}${systemd_unitdir}/network/80-wired.network
 }
 
 # Based on change from YP bug 8141, OE commit 5196d7bacaef1076c361adaa2867be31759c1b52
 do_install_append_qemuall() {
 	install -D -m0644 ${WORKDIR}/system.conf-qemuall ${D}${systemd_unitdir}/system.conf.d/01-${PN}.conf
+
+	# Do not install wired.network for qemu bsps
+	rm -rf ${D}${systemd_unitdir}/network
 }
 
 PACKAGE_ARCH = "${MACHINE_ARCH}"
@@ -29,4 +34,5 @@ FILES_${PN} = "\
     ${systemd_unitdir}/journald.conf.d/ \
     ${systemd_unitdir}/logind.conf.d/ \
     ${systemd_unitdir}/system.conf.d/ \
+    ${systemd_unitdir}/network/ \
 "