Add support for aes counter(ctr) block cipher mode of operation for
Exynos Hardware. In contrast to ecb and cbc modes, aes-ctr allows
encyption/decryption for request sizes not being a multiple of 16(bytes).

Hardware requires block sizes being a multiple of 16(bytes). In order to
achieve this, copy request source and destination memory, and align it's size
to 16. That way hardware processes additional bytes, that are omitted
when copying the result back to its original destination.

Tested on Odroid-U3 with Exynos 4412 CPU, kernel 4.19-rc2 with crypto
run-time self test testmgr.
Signed-off-by: Christoph Manszewski <c.manszewski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>