msm: cpufreq: Fix store_powersave_bias to account for sync' CPUs.

Current code assumes that all online CPUs runs their own timers to
collect CPU samples for demand based switching (dbs). But in case of
synchronous CPUs ondemand governor registers only one timer at init
time because both CPUs are accounted in the same timer call. Hence
trying to restart/cancel dbs timers for all online CPUs is not legal
for these CPUs. This change fixes above function to restart/cancel
timers only once for group of synchronous CPUs.

CRs-Fixed: 348502
Signed-off-by: Krishna Vanka <kvanka@codeaurora.org>
(cherry picked from commit 3d5b6bd91f28ecbc90f233f3a2854e4496d619bc)

Change-Id: Ia69841655929f5e5306ca7e1865d7b0125cd8ead
Signed-off-by: Sunil Joseph <sunilj@codeaurora.org>