IB/rxe: Offload CRC calculation when possible

Use CPU ability to perform CRC calculations, by
replacing direct calls to crc32_le() with crypto_shash_updata().

The overall performance gain measured with ib_send_bw tool is 10% and it
was tested on "Intel CPU ES-2660 v2 @ 2.20Ghz" CPU.

ib_send_bw -d rxe0  -x 1 -n 9000 -e  -s $((1024 * 1024 )) -l 100

---------------------------------------------------------------------------------------------
|             | bytes   | iterations | BW peak[MB/sec] | BW average[MB/sec] | MsgRate[Mpps] |
---------------------------------------------------------------------------------------------
| crc32_le    | 1048576 | 9000       | inf             | 497.60             | 0.000498      |
| CRC offload | 1048576 | 9000       | inf             | 546.70             | 0.000547      |
---------------------------------------------------------------------------------------------

Fixes: 8700e3e7

 ("Soft RoCE driver")
Signed-off-by: Yonatan Cohen <yonatanc@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>