msm: vidc: Add msm_vidc_wait as a poll interface for kernel clients

Add a new interface msm_vidc_wait that is similar to msm_vidc_poll in
functionality, except intended for kernel-space clients.

Change-Id: Ia08f228f9865dcb8c92ba8fc04692e4b0184daea
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>