meta-phosphor: unset VOLATILE_LOG_DIR

This variable, if set, creates a symlink of /var/log to
/var/volatile/log.  In most cases if machines have configured
applications like obmc-console or journald to write to /var/log
they want it to be persistent.  The symlink causes them to be written
to the non-persistent tmpfs space for /var/volatile.

Set all machines to `VOLATILE_LOG_DIR = no` by default.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I0f973e6b8599b32451c83d5161be079e967de711
diff --git a/meta-ampere/meta-jade/conf/machine/mtjade.conf b/meta-ampere/meta-jade/conf/machine/mtjade.conf
index 8573229..1a616aa 100644
--- a/meta-ampere/meta-jade/conf/machine/mtjade.conf
+++ b/meta-ampere/meta-jade/conf/machine/mtjade.conf
@@ -21,8 +21,6 @@
         obmc-host-ipmi \
         "
 
-VOLATILE_LOG_DIR = "no"
-
 OBMC_COMPATIBLE_NAMES = "com.ampere.Hardware.Chassis.Model.MtJade"
 
 OBMC_IMAGE_EXTRA_INSTALL:append = "\
diff --git a/meta-ampere/meta-mitchell/conf/machine/mtmitchell.conf b/meta-ampere/meta-mitchell/conf/machine/mtmitchell.conf
index 3b40661..24b24dd 100644
--- a/meta-ampere/meta-mitchell/conf/machine/mtmitchell.conf
+++ b/meta-ampere/meta-mitchell/conf/machine/mtmitchell.conf
@@ -12,7 +12,6 @@
 require conf/distro/include/pldm.inc
 
 FLASH_SIZE = "65536"
-VOLATILE_LOG_DIR = "no"
 
 OBMC_COMPATIBLE_NAMES = "com.ampere.Hardware.Chassis.Model.MtMitchell"
 
diff --git a/meta-phosphor/conf/distro/include/phosphor-base.inc b/meta-phosphor/conf/distro/include/phosphor-base.inc
index e312caf..b830453 100644
--- a/meta-phosphor/conf/distro/include/phosphor-base.inc
+++ b/meta-phosphor/conf/distro/include/phosphor-base.inc
@@ -85,6 +85,10 @@
 # /root, but we should switch it back (and maybe adjust in another commit).
 ROOT_HOME = "/home/root"
 
+# We want to persist /var/log, which is likely to be used for
+# obmc-console and/or journald.
+VOLATILE_LOG_DIR = "no"
+
 DISTRO_FEATURES_BACKFILL_CONSIDERED = " \
         bluez5 \
         ldconfig \