Add Macroblock based rate control method.
Add Macroblock based rate control method.

Signed-off-by: pylee <bb9a1fd0c1d9610887ae1d1419fc92ffd66b6994@intel.com>
Reviewed-By: Sean V Kelley <56c4ee8950656f8ee63ca686448cb9aeaf109ab0@intel.com>

01org/libva-cros,01org/iotg-lin-gfx-libva,01org/iotg-lin-gfx-libva,01org/libva-cros,01org/libva-cros,01org/iotg-lin-gfx-libva