dbus-dir: change static dbus config directory

Move static dbus config directory to be `/usr/share` instead of `/etc`,
which is recommended by `dbus-daemon`.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ifd210a262e1c8025dc9e3037c9970ec66ebb085b
diff --git a/meta-phosphor/classes/dbus-dir.bbclass b/meta-phosphor/classes/dbus-dir.bbclass
index f663463..a8ed3e7 100644
--- a/meta-phosphor/classes/dbus-dir.bbclass
+++ b/meta-phosphor/classes/dbus-dir.bbclass
@@ -1,2 +1,2 @@
-dbus_system_confdir="${sysconfdir}/dbus-1/system.d/"
+dbus_system_confdir="${datadir}/dbus-1/system.d/"
 dbus_system_servicesdir="${datadir}/dbus-1/system-services/"