cpufreq: Add a sync limit to cpu-boost

Perform frequency synchronization only when source CPU's frequency
is less than sync_threshold, else sync to the sync_threshold.

Change-Id: I544c414568d4e015b80ce5891dd215275bac95da
Signed-off-by: Rohit Gupta <rohgup@codeaurora.org>
Signed-off-by: revjunkie <gadgetjuan@gmail.com>
cpufreq: Add Input Boost feature to the cpu-boost driver

Signed-off-by: revjunkie <gadgetjuan@gmail.com>