[CRYPTO] scatterwalk: Move scatterwalk.h to linux/crypto

The scatterwalk infrastructure is used by algorithms so it needs to
move out of crypto for future users that may live in drivers/crypto
or asm/*/crypto.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/gcm.c b/crypto/gcm.c
index d60c340..27483f3 100644
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -10,13 +10,14 @@
 
 #include <crypto/algapi.h>
 #include <crypto/gf128mul.h>
+#include <crypto/scatterwalk.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 
-#include "scatterwalk.h"
+#include "internal.h"
 
 struct gcm_instance_ctx {
 	struct crypto_spawn ctr;