cryptodev: formalize key wrap method in API

The Key Wrap approach is used by applications in order to protect keys
located in untrusted storage or transmitted over untrusted
communications networks. The constructions are typically built from
standard primitives such as block ciphers and cryptographic hash
functions.

The Key Wrap method and its parameters are a secret between the keys
provider and the device, means that the device is preconfigured for
this method using very secured way.

The key wrap method may change the key length and layout.

Add a description for the cipher transformation key to allow wrapped key
to be forwarded by the same API.

Add a new feature flag RTE_CRYPTODEV_FF_CIPHER_WRAPPED_KEY to be enabled
by PMDs support wrapped key in cipher trasformation.

Signed-off-by: Matan Azrad <matan@nvidia.com>
Acked-by: Akhil Goyal <gakhil@marvell.com>