meta-phosphor: set INIT_MANAGER

Since Yocto's 3.0 release[1], the preferred way to set the init system
is through the INIT_MANAGER variable rather than tweaking specific
variables.  Set this variable to `systemd` and clean up the specific
tweaks we've done that are already handled as a side-effect of the
INIT_MANAGER setting.

[1]. https://github.com/openbmc/openbmc/blob/master/poky/documentation/migration-guides/migration-3.0.rst#init-system-selection

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I6ee8375ed0ec80f854f0811898b6979f0c62a358
diff --git a/meta-phosphor/conf/distro/include/phosphor-base.inc b/meta-phosphor/conf/distro/include/phosphor-base.inc
index 7ded76d..e312caf 100644
--- a/meta-phosphor/conf/distro/include/phosphor-base.inc
+++ b/meta-phosphor/conf/distro/include/phosphor-base.inc
@@ -75,18 +75,21 @@
 DISTRO_NAME ?= "Phosphor OpenBMC (Phosphor OpenBMC Project Reference Distro)"
 TARGET_VENDOR="-openbmc"
 
+
 VIRTUAL-RUNTIME_keymaps = ""
 
 # Phosphor OpenBMC uses systemd and udev
-VIRTUAL-RUNTIME_init_manager = "systemd"
-VIRTUAL-RUNTIME_initscripts = ""
+INIT_MANAGER = "systemd"
+# systemd doesn't like us using /home/root instead of /root but we've been
+# doing it a long time.  The `INIT_MANAGER = systemd` switches the default to
+# /root, but we should switch it back (and maybe adjust in another commit).
+ROOT_HOME = "/home/root"
 
 DISTRO_FEATURES_BACKFILL_CONSIDERED = " \
         bluez5 \
         ldconfig \
         gobject-introspection-data \
         pulseaudio \
-        sysvinit \
         "
 
 DISTRO_FEATURES_OBMC = " \
@@ -105,9 +108,7 @@
         pam \
         security \
         slp \
-        systemd \
         seccomp \
-        usrmerge \
         "
 
 DISTRO_FEATURES += " \