proc: Add files for specifying scheduling related per-task attributes

Add procfs files for specifying the scheduling related per-task
attributes like wake_up_idle, init_task_load and sched_group_id.

Change-Id: I97db385522c7317fbc6f78cbae5c2550b73afd27
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Puja Gupta <pujag@codeaurora.org>
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>