use BlockDifference to do the patching for shamu radio image

A plain bsdiff often performs poorly on radio images because they
contain large regions of all-zero blocks, which is a bad case for
bsdiff's suffix sort.

Change to using the new block image stuff, which pulls these blocks
out and handles them separately.

Change-Id: Id9b57fb97f9d3de53277507e0dc3ae622b9b43ac
1 file changed