sched: bring in missing change in boost, fix minor issues in tune & walt

While bringing in boost changes as part of commit bb5b6b3e
("sched: Add snapshot of Window Assisted Load Tracking (WALT)"),
looks like kick_mask in boost_kick_cpus function wasn't picked
properly. Update the same to be in sync with msm-4.9.

Also, fix indetation issues in tune and remove unused cpu variable
in walt.

Change-Id: If20120bddd51236de08f0714a956aa3b5534201b
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>