If IMB_MGR is NULL, errno is set in global variable.
If key parameter is NULL, but IMB_MGR is NULL, the errno is set
inside IMB_MGR.

- perform all plain text loads before doing stores
- without the workaround, on Intel Atom(R) processors, performance penalty may be observed
  in NOT 4-byte aligned address and an in-place operation

- add new include file for aes-cbc encrypt based algorithms
- use macro from the new include file for aes-cbc encrypt, aes-cmac and aes-xcbc

Co-authored-by: Tomasz Kantecki <tomasz.kantecki@intel.com>

kat-app: improve README.md format

Keystream generation function using GFNI was not always
used when GFNI instructions are available.

The goal of this application is to showcase
how to use the ipsec-mb API by encrypting
several buffers with AES-GCM, using the new burst API.