BACKPORT: crypto: zstd - Add zstd support

Adds zstd support to crypto and scompress. Only supports the default
level.

Previously we held off on this patch, since there weren't any users.
Now zram is ready for zstd support, but depends on CONFIG_CRYPTO_ZSTD,
which isn't defined until this patch is in. I also see a patch adding
zstd to pstore [0], which depends on crypto zstd.

[0] lkml.kernel.org/r/9c9416b2dff19f05fb4c35879aaa83d11ff72c92.1521626182.git.geliangtang@gmail.com

Signed-off-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

(cherry picked from commit d28fc3db)
Signed-off-by: Peter Kalauskas <peskal@google.com>
Bug: 112488418
Change-Id: I070acf1dd8bf415f8997a48ee908d930754fc71e
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>