Update the LZ4 compression module based on LZ4 v1.8.3 in order to
use the newest LZ4_decompress_safe_partial() which can now decode
exactly the nb of bytes requested.

Signed-off-by: Huang Jianan <jnhuang95@gmail.com>

Sphinx expects Return: and not @return to indicate a return value.

find . -name '*.c' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

find . -name '*.h' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

At present U-Boot has a header file called lz4.h for its own use. If the
host has its own lz4 header file installed (e.g. from the 'liblz4-dev'
package) then host builds will use that instead.

Move the U-Boot file into its own directory, as is done with various
other headers with the same problem.

Signed-off-by: Simon Glass <sjg@chromium.org>