fs/erofs: add DEFLATE algorithm support

This patch adds DEFLATE compression algorithm support. It's a good choice
to trade off between compression ratios and performance compared to LZ4.
Alternatively, DEFLATE could be used for some specific files since EROFS
supports multiple compression algorithms in one image.

Signed-off-by: Jianan Huang <jnhuang95@gmail.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>