Provide a valid reference for the deflate format.
Reformat the ALGORITHM and REFERENCES comments.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Add a new config CONFIG_GZIP_ENABLED, if enabled, the uboot bin would
include zlib's deflate method which could be used for compressing.
Signed-off-by: Lei Wen <leiwen@marvell.com>