build: Install dbus policy in datadir

sysconfdir is intended to be used by system administrator configurations
and not directly installed by packages.

https://dbus.freedesktop.org/doc/dbus-daemon.1.html

Change-Id: I3434ad09f6630142aa83302abeeb982506f9a5a2
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/dist/meson.build b/dist/meson.build
index cda6084..a38f80b 100644
--- a/dist/meson.build
+++ b/dist/meson.build
@@ -11,5 +11,5 @@
 install_data(
     ['busconfig/phosphor-logging.conf',
      'busconfig/phosphor-rsyslog-config.conf'],
-    install_dir: get_option('sysconfdir') / 'dbus-1/system.d'
+    install_dir: get_option('datadir') / 'dbus-1' / 'system.d'
 )