ARM: msm_defconfig: Enable service notifier

Enable the kernel client api for the service notifier. Since
this feature is needed for internal prototyping, do not enable
it on perf builds for performance reasons.

Change-Id: I9146ccc244e76f1c11b08cbf19972fdc1a9aa8dc
Signed-off-by: Pushkar Joshi <pushkarj@codeaurora.org>