Follow the steps: https://github.com/facebook/zstd/blob/v1.5.7/contrib/linux-kernel/README.md
The following committed changes are also preserved:
70168143b302378ccff178bf28cb140c783dac88 zstd: merge optimization from Samsung <DevriesL>
0b893588096921a258f8ca27d6005da4201c9b58 lib: zstd: Don't inline functions in zstd_opt.c <Nick Terrell>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>