Add the missing code to allow bzip2 compression to be used. This is useful
for sandbox tests. These files are taken from the bzip2 1.0.6 release.
The license text is copied to the top of each file as is done with other
bzip2 files in U-Boot. The only other change is to squash a compiler warning
with nBytes.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>