HW generates a Data Size error for chacha20 requests that are not
a multiple of 64B, since algorithm state (AS) does not have
the FINAL bit set.

Since updating req->iv (for chaining) is not required,
modify skcipher descriptors to set the FINAL bit for chacha20.

[Note that for skcipher decryption we know that ctx1_iv_off is 0,
which allows for an optimization by not checking algorithm type,
since append_dec_op1() sets FINAL bit for all algorithms except AES.]

Also drop the descriptor operations that save the IV.
However, in order to keep code logic simple, things like
S/G tables generation etc. are not touched.

Cc: <stable@vger.kernel.org> # v5.3+
Fixes: 334d37c9 ("crypto: caam - update IV using HW support")
Signed-off-by: NHoria Geantă <horia.geanta@nxp.com>
Tested-by: NValentin Ciocoi Radulescu <valentin.ciocoi@nxp.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>