s390/zcrypt: ep11 structs rework, export zcrypt_send_ep11_cprb

Minor rework for struct ep11_cprb and struct ep11_urb. Use of u8, u16,
u32 instead of unsigned char. Declare pointers to mem from userspace
with __user to give sparse a chance to check.

Export zcrypt_send_ep11_cprb() function as this function will be
called by code in progress which will build ep11 cprbs within the
zcrypt device driver zoo and send them to EP11 crypto cards.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>