sched: Add missing bits of HMP scheduling

The upgrade of the HMP scheduler to the latest kernel versions
introduced some bugs due to missing changes. Add these missing
parts back so that the HMP scheduler can function without errors.

Change-Id: I7b7223462c91871ccc247d872353808fac74fcad
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>