Add the mmx and sse2 implementations of ff_snow_vertical_compose().

Patch by Robert Edele < yartrebo AH earthlink POIS net >
Original thread:
Date: Mar 20, 2006 5:54 PM
Subject: [Ffmpeg-devel] [PATCH] snow mmx + sse2 part 3

Originally committed as revision 5185 to svn://svn.ffmpeg.org/ffmpeg/trunk