board/raspberrypi: enable hdmi console for systemd

Most of the users use HDMI console on RPi and with increasing popularity
of systemd they face a trouble.
systemd doesn't use /etc/inittab, enable getty@tty1.service instead.

Signed-off-by: Alexey Roslyakov <alexey.roslyakov@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit c415820662661a6ef3cc8b2d9ea1a79791c1d7eb)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

board/raspberrypi/post-build.sh

@@ -8,6 +8,11 @@ if [ -e ${TARGET_DIR}/etc/inittab ]; then
     grep -qE '^tty1::' ${TARGET_DIR}/etc/inittab || \
 	sed -i '/GENERIC_SERIAL/a\
 tty1::respawn:/sbin/getty -L  tty1 0 vt100 # HDMI console' ${TARGET_DIR}/etc/inittab
+# systemd doesn't use /etc/inittab, enable getty.tty1.service instead
+elif [ -d ${TARGET_DIR}/etc/systemd ]; then
+    mkdir -p "${TARGET_DIR}/etc/systemd/system/getty.target.wants"
+    ln -sf /lib/systemd/system/getty@.service \
+       "${TARGET_DIR}/etc/systemd/system/getty.target.wants/getty@tty1.service"
 fi
 
 # exnsure overlays exists for genimage