msm: pm: Set affinity of PM irqs to next scheduled CPU

Modify the affinity of the interrupts associated with PM driver to the cpu
that will wakeup for the next expiring timer.

Change-Id: I6a1b25538a6d12bada3345a17b3ed4ff181ac089
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>