va: Add a flag to signal APP whether the driver support raw packed header
va: Add a flag to signal APP whether the driver support raw packed header

Modify the comments for VAEncPackedHeaderRawData as well

Signed-off-by: Xiang, Haihao <8d677183e5993577d4fa73a419b76987913292d6@intel.com>

halleyzhao/libva-fdo,halleyzhao/libva-fdo,android-ia/hardware_intel_libva,android-ia/hardware_intel_libva,CyanogenMod/android_hardware_intel_libva,CyanogenMod/android_hardware_intel_libva,android-ia/hardware_intel_libva,CyanogenMod/android_hardware_intel_libva,halleyzhao/libva-fdo