s390/zcrypt: Remove deprecated zcrypt proc interface.

This patch removes the deprecated zcrypt proc interface.
It is outdated and deprecated and does not support the
latest 3 generations of CEX cards.

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