Zstd is supported by the crypto API since Linux 4.18. Enable this feature and
reveal the package in the configuration section, so the user can select it.
This allows zstd to be used as a compression algorithm in zram, for example.
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
Zram is only strictly dependent on lzo, not lz4. Break this dependency and
make the lz4 module visible in the configuration, in order for the user to
have the choice of enabling/disabling it, if (s)he sees fit.
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
