cpu-boost: Fix cores getting stuck. Finally.
* In exclusive hotplug system, if a core is not taken down
  explicitly, it is observed that it gets stuck at input
  boost frequency.
* This issue maybe particular to only this kernel but this
  fix resolves it completely.
* Root cause seems to be removal work is lost if queued on
  sibling cores. So simply fix this by queuing on boot CPU.

* Finally, I can use min_cpus_online > 1 without any issue.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
cpufreq: cpu-boost: Implement additional checks

* Return early without calculations if last
  input_boost_work is pending.
* Disable input boost if input_boost_freq value is
  less than or equal to min possible frequency.
* Disable hotplug boost if plug_boost_freq value is
  less than or equal to min possible frequency.
* When we check for current frequency greater than
  boost frequency, also check if boost is removed
  properly or not. If not, do so.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
cpufreq: cpu-boost: Unify input and hotplug boost

* This doesn't make sense to have mirror functions
  operating different boost frequencies.
* If input_boost_freq > hotplug_boost_freq, hotplug
  boost will be rendered useless in most case since
  parallel input boost will be doing it work.
* So instead having separate boost functions,
  keep only single boost function "do_input_boost"
  and let hotplug callback access this boost.
* Disable hotplug boost by default and provide
  attribute for same.

* Increased migration_load_threshold to prevent
  not-so-needed and recurring migrations.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>

Conflicts:
	drivers/cpufreq/cpu-boost.c
cpufreq: cpu-boost: Do not consider keypad events for boost

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>