1. Add buf_grp, buf_grp_cfg, buffer, buf_cfg objdef.
2. The buf_grp_cfg is binded to buf_grp and the buf_cfg is binded to
buffer. The binding cfg obj is stored in private data.
Change-Id: I9243c03f7b9519536fdc2f24b62761dc04baac85
Signed-off-by: Yanjun Liao <yanjun.liao@rock-chips.com>
Signed-off-by: Herman Chen <herman.chen@rock-chips.com>
