msm: timer: read timer twice on 9615

There is an issue with the KPSS where sometimes timer reads can be
corrupted if done while the timer is updating. Fix this by reading
twice, and ensuring successive reads are at most one tick apart.

Change-Id: I77c096699961421e0f655638302b7fa97c8398bd
Signed-off-by: Jeff Ohlstein <johlstei@codeaurora.org>