msm: pm-8x60: Use relative time for events

There is a bug when adjusting for event wakeups. The adjusted time
is being set in absolute mode incorrectly. Instead just use relative
times.

Without this core wakeups may not happen on time.

CRs-fixed: 486466
Change-Id: If625f25bd573b05befb6e0f922c80db646428b86
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>