crypto: hash - Move ahash functions into crypto/hash.h

All new crypto interfaces should go into individual files as much
as possible in order to ensure that crypto.h does not collapse under
its own weight.

This patch moves the ahash code into crypto/hash.h and crypto/internal/hash.h
respectively.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/digest.c

@@ -12,6 +12,7 @@
  *
  */
 
+#include <crypto/internal/hash.h>
 #include <crypto/scatterwalk.h>
 #include <linux/mm.h>
 #include <linux/errno.h>