Slim_ngd: Modify waiting mechanism in kthread

wait_for_completion_timeout() is not a good option in
kthread as it leads to scheduling the kthread on the every timeout.
Hence modify it to wait_for_completion() from
wait_for_completion_timeout().

Change-Id: Iaa29e997fd1cd5cb02f9ba44e69e1700b31736ae
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>