KVM: s390: selftests: Add regression tests for PRNO, KDSA and KMA crypto subfunctions

KVM: s390: selftests: Add regression tests for PRNO, KDSA and KMA crypto subfunctions

Extend the existing regression test framework for s390x CPU subfunctions
to include tests for the PRNO (Perform Random Number Operation), KDSA
(Compute Digital Signature Authentication) and KMA (Cipher Message with
Authentication) crypto functions.

The test procedure follows the established pattern:

1. Obtain KVM_S390_VM_CPU_MACHINE_SUBFUNC attribute for the VM.
2. Execute PRNO, KDSA and KMA instructions.
3. Compare KVM-reported results with direct instruction execution results.

Suggested-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Hariharan Mari <hari55@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Link: https://lore.kernel.org/r/20240823130947.38323-3-hari55@linux.ibm.com
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-ID: <20240823130947.38323-3-hari55@linux.ibm.com>