Rework of the pkey code. Moved all the cca generic code
away from pkey_api.c into a new file zcrypt_ccamisc.c.
This new file is now part of the zcrypt device driver
and exports a bunch of cca functions to pkey and may
be called from other kernel modules as well.

The pkey ioctl API is unchanged.
Signed-off-by: NHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: NIngo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>