crypto: speck - add test vectors for Speck64-XTS

Add test vectors for Speck64-XTS, generated in userspace using C code.
The inputs were borrowed from the AES-XTS test vectors, with key lengths
adjusted.

xts-speck64-neon passes these tests.  However, they aren't currently
applicable for the generic XTS template, as that only supports a 128-bit
block size.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

crypto/testmgr.c

@@ -3584,6 +3584,15 @@ static const struct alg_test_desc alg_test_descs[] = {
 				.dec = __VECS(speck128_xts_dec_tv_template)
 			}
 		}
+	}, {
+		.alg = "xts(speck64)",
+		.test = alg_test_skcipher,
+		.suite = {
+			.cipher = {
+				.enc = __VECS(speck64_xts_enc_tv_template),
+				.dec = __VECS(speck64_xts_dec_tv_template)
+			}
+		}
 	}, {
 		.alg = "xts(twofish)",
 		.test = alg_test_skcipher,