[dbus-writer] limit d-bus traffic

Limit d-bus traffic by only sending updates, instead
of every value.

Tested-by: used d-bus monitor and noticed significantly
reduced messages.

Change-Id: Ie677feaedab4e9ebb14950392b9588d4d82c0058
Signed-off-by: James Feist <james.feist@linux.intel.com>
2 files changed