API: h264 encode: add more explicit packed header types for H.264.
API: h264 encode: add more explicit packed header types for H.264.

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