Add MppEncRefCfg for reference frame relationship configure.
MppEncRefCfg is for user to setup its own gop reference hierarchy.
Setup flow:
mpp_enc_ref_cfg_get_preset (can be ommitted, helper for setup lt/st cfg)
mpp_enc_ref_cfg_init
mpp_enc_ref_cfg_set_cfg_cnt
mpp_enc_ref_cfg_add_lt_cfg (can be omitted)
mpp_enc_ref_cfg_add_st_cfg
mpp_enc_ref_cfg_check (IMPORTANT: need to check before contol to mpp)
control to mpp
mpp_enc_ref_cfg_deinit
Change-Id: Ia0f5c4c713a4b11d8e4e5581609f8501f36549cc
Signed-off-by: Herman Chen <herman.chen@rock-chips.com>
