soc: qcom: Use config to disable ipi optimization

Enable watchdog ipi optimization by default, which makes
watchdog to not send ipi to cores in low power mode at pet time.

Add config option to control the optimization.

Change-Id: Id6a166a16ad6828cd63ec376ae263c5263494628
Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org>