lib/md5: Export progressive APIs

Export the MD5 hash init/update/finish progressive APIs
for better flexibility.

Signed-off-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com>

include/u-boot/md5.h

@@ -17,6 +17,10 @@ struct MD5Context {
 	};
 };
 
+void MD5Init(struct MD5Context *ctx);
+void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len);
+void MD5Final(unsigned char digest[16], struct MD5Context *ctx);
+
 /*
  * Calculate and store in 'output' the MD5 digest of 'len' bytes at
  * 'input'. 'output' must have enough space to hold 16 bytes.