meta-phosphor: Move to dbus-broker

Dbus-broker is an alternative implementation of the dbus-daemon that is
oriented around reducing abnormal conditions, and increasing the
performance of the dbus daemon process.

In practice, this seems to make a world of difference in performance.  A
testing of a smattering of user facing interfaces shows improvements
across the board:
1. 7 second improvement in boot time to BMC Ready change.
2. Dbus based ipmi sensor reading implementation gains a 120% speedup
(20 seconds down to 8)
3. Redfish thermal schema goes from 550ms time to first byte, to 400ms
time to first byte.

Negatives as they apply to OpenBMC
1. Debug: dbus-broker loses the ability to directly implement DBus over
TCP.  To my knowlege very few people use this for anything other than
debug, and even for debug, its usefulness is limited.  It's very likely
that an implementation of socat could bridge this gap.
2. Support.  Very few other linux implementations have moved to dbus
broker, so there is the possibility that we will find a critical flaw or
bug that others haven't hit get.  This seems relatively unlikely, given
the widespread usage of this project already.

Tested By: Booting system, and testing a variety of user facing
interfaces.  No issues found.

Requires Williams patch cherry picked ontop of oe-core:
http://cgit.openembedded.org/meta-openembedded/commit/meta-oe/recipes-core/dbus/dbus-broker_git.bb?id=e4baf298cd658b37fd90134dc54a92c75fd117d9

(From meta-phosphor rev: 72615f5614abba33a14d68afdb9010c93f3a1ea3)

Change-Id: Iabac84c93253aa96c7735db4f1e0755d37e6c3db
Signed-off-by: Ed Tanous <ed.tanous@intel.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-phosphor/recipes-phosphor/packagegroups/packagegroup-obmc-apps.bb b/meta-phosphor/recipes-phosphor/packagegroups/packagegroup-obmc-apps.bb
index 28b903d..1a178a9 100644
--- a/meta-phosphor/recipes-phosphor/packagegroups/packagegroup-obmc-apps.bb
+++ b/meta-phosphor/recipes-phosphor/packagegroups/packagegroup-obmc-apps.bb
@@ -39,6 +39,7 @@
         phosphor-rest \
         phosphor-dbus-monitor \
         phosphor-systemd-policy \
+        dbus-broker \
         "
 
 SUMMARY_${PN}-extrasdev = "Development features"