msm: vidc: Add support for setting initial qp

Adds support to set initial qp, thereby allowing the client to set
initial qp for I,P, and B frames.

Change-Id: Ie956651bde85e800d97a0007769af9aec8ca16a4
Signed-off-by: Ashray Kulkarni <ashrayk@codeaurora.org>

Conflicts:
	drivers/media/platform/msm/vidc/hfi_packetization.c
	drivers/media/platform/msm/vidc/msm_venc.c
	drivers/media/platform/msm/vidc/vidc_hfi_api.h
	include/linux/videodev2.h

(Only headers)