API: h264 encode: remove dec_ref_pic_marking().
API: h264 encode: remove dec_ref_pic_marking().

01org/iotg-lin-gfx-libva,chenxianqin/vaapi-libva,01org/iotg-lin-gfx-libva,01org/iotg-lin-gfx-libva,pma1/libva,gbeauchesne/libva,01org/libva-cros,pma1/libva,chenxianqin/vaapi-libva,01org/libva-cros,zzhhui/libva,gbeauchesne/libva,gbeauchesne/libva,chenxianqin/vaapi-libva,zzhhui/libva,pma1/libva,zzhhui/libva,01org/libva-cros