crypto/krb5: Implement crypto self-testing

Implement self-testing infrastructure to test the pseudo-random function,
key derivation, encryption and checksumming.

Add the testing data from rfc8009 to test AES + HMAC-SHA2.

Add the testing data from rfc6803 to test Camellia.  Note some encryption
test vectors here are incomplete, lacking the key usage number needed to
derive Ke and Ki, and there are errata for this:

	https://www.rfc-editor.org/errata_search.php?rfc=6803



Signed-off-by: David Howells <dhowells@redhat.com>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: "David S. Miller" <davem@davemloft.net>
cc: Chuck Lever <chuck.lever@oracle.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: linux-nfs@vger.kernel.org
cc: linux-crypto@vger.kernel.org
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