msm: vidc: add LTR support for video encoder

Enable LTR support for VP8 codec to add robust error resilience.

Change-Id: I3b87c5cdaef836a6d02d5b9fe71b7165b7f13581
Signed-off-by: Ashray Kulkarni <ashrayk@codeaurora.org>

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

Conflicts:
	drivers/media/platform/msm/vidc/hfi_packetization.c
	drivers/media/platform/msm/vidc/vidc_hfi_api.h