cryptodev: restore crypto op alignment and layout

cryptodev: restore crypto op alignment and layout

in 18.08 new cache-aligned structure rte_crypto_asym_op was introduced.
As it also was included into rte_crypto_op, it caused implicit change
in rte_crypto_op layout and alignment: now rte_crypto_op is cache-line
aligned has a hole of 40/104 bytes between phys_addr and sym/asym op.
It looks like unintended ABI breakage, plus such change can cause
negative performance effects:
- now status and sym[0].m_src lies on different cache-lines, so
  post-process code would need extra cache-line read.
- new alignment causes grow of the space requirements and cache-line
  reads/updates for structures that contain rte_crypto_op inside.
As there seems no actual need to have rte_crypto_asym_op cache-line
aligned, and rte_crypto_asym_op is not intended to be used on it's own -
the simplest fix is just to remove cache-line alignment for it.
As the immediate positive effect: on IA ipsec-secgw performance increased
by 5-10% (depending on the crypto-dev and algo used).
My guess that on machines with 128B cache-line and lookaside-protocol
capable crypto devices the impact will be even more noticeable.

Fixes: 26008aaed14c ("cryptodev: add asymmetric xform and op definitions")
Cc: stable@dpdk.org
Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Fiona Trahe <fiona.trahe@intel.com>
Acked-by: Shally Verma <shallyv@marvell.com>
Acked-by: Akhil Goyal <akhil.goyal@nxp.com>