crypto: skcipher - add crypto_skcipher_min_keysize()

Add a helper function crypto_skcipher_min_keysize() to mirror
crypto_skcipher_max_keysize().

This will be used by the self-tests.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/crypto/skcipher.h

@@ -368,6 +368,12 @@ static inline int crypto_sync_skcipher_setkey(struct crypto_sync_skcipher *tfm,
 	return crypto_skcipher_setkey(&tfm->base, key, keylen);
 }
 
+static inline unsigned int crypto_skcipher_min_keysize(
+	struct crypto_skcipher *tfm)
+{
+	return crypto_skcipher_alg(tfm)->min_keysize;
+}
+
 static inline unsigned int crypto_skcipher_max_keysize(
 	struct crypto_skcipher *tfm)
 {