s390/zcrypt: zcrypt device driver cleanup

Some cleanup in the s390 zcrypt device driver:
- Removed fragments of pcixx crypto card code. This code
  can't be reached anymore because the hardware detection
  function does not recognize crypto cards < CEX2 since
  commit f56545430736 ("s390/zcrypt: Introduce QACT support
  for AP bus devices.")
- Rename of some files and driver names which where still
  reflecting pcixx support to cex2a/cex2c.
- Removed all the zcrypt version strings in the file headers.
  There is only one place left - the zcrypt.h header file is
  now the only place for zcrypt device driver version info.
- Zcrypt version pump up from 2.2.0 to 2.2.1.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>