vidc: Add metabuffer mode support for encoder driver.

Video encoder driver when configured in meta buffer mode,
will allow clients to register buffers in data path.

Change-Id: I23e2cb07386461275da5731134d8aad7df1cd060
Signed-off-by: Gopikrishnaiah Anandan <gopikr@codeaurora.org>

Conflicts:

	drivers/video/msm/vidc/1080p/ddl/vcd_ddl_properties.c
	drivers/video/msm/vidc/common/enc/venc.c
	drivers/video/msm/vidc/common/vcd/vcd_client_sm.c
	drivers/video/msm/vidc/common/vcd/vcd_core.h
	drivers/video/msm/vidc/common/vcd/vcd_property.h
	include/linux/msm_vidc_enc.h

Signed-off-by: Braydon Saporito <altabraydon@gmail.com>