Patch from Alexander Schulz

Up to now, shark kernels were limited to one megabyte compressed
size. As the kernels get bigger, this becomes more and more
uncomfortable. So I added a loop to copy 3 MB instead of one
and added some comments.
Signed-off-by: Alexander Schulz <alex@shark-linux.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>