cpufreq: cpu-boost: Use one work to remove input boost for all CPUs

Currently each CPU queues up its own work for removing input boost.
This is not really required as boost removal for all the CPUs can
be done at the same time. So this patch uses a single work to
remove input boost for all the CPUs and updates the policy for
the online ones.

Change-Id: I37c809f2f155548b1d8c1b9aa7626c8852b3acc6
Signed-off-by: Rohit Gupta <rohgup@codeaurora.org>