crypto: sha256 - Merge crypto/sha256.h into crypto/sha.h

The generic sha256 implementation from lib/crypto/sha256.c uses data
structs defined in crypto/sha.h, so lets move the function prototypes
there too.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/include/crypto/sha.h b/include/crypto/sha.h
index 8a46202..535955c 100644
--- a/include/crypto/sha.h
+++ b/include/crypto/sha.h
@@ -112,4 +112,25 @@ extern int crypto_sha512_update(struct shash_desc *desc, const u8 *data,
 
 extern int crypto_sha512_finup(struct shash_desc *desc, const u8 *data,
 			       unsigned int len, u8 *hash);
+
+/*
+ * Stand-alone implementation of the SHA256 algorithm. It is designed to
+ * have as little dependencies as possible so it can be used in the
+ * kexec_file purgatory. In other cases you should generally use the
+ * hash APIs from include/crypto/hash.h. Especially when hashing large
+ * amounts of data as those APIs may be hw-accelerated.
+ *
+ * For details see lib/crypto/sha256.c
+ */
+
+extern int sha256_init(struct sha256_state *sctx);
+extern int sha256_update(struct sha256_state *sctx, const u8 *input,
+			 unsigned int length);
+extern int sha256_final(struct sha256_state *sctx, u8 *hash);
+
+extern int sha224_init(struct sha256_state *sctx);
+extern int sha224_update(struct sha256_state *sctx, const u8 *input,
+			 unsigned int length);
+extern int sha224_final(struct sha256_state *sctx, u8 *hash);
+
 #endif