crypto: add module.h to those files that are explicitly using it

Part of the include cleanups means that the implicit
inclusion of module.h via device.h is going away.  So
fix things up in advance.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/crypto/md4.c b/crypto/md4.c
index 7fca1f59..0477a6a 100644
--- a/crypto/md4.c
+++ b/crypto/md4.c
@@ -23,6 +23,7 @@
 #include <crypto/internal/hash.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/string.h>
 #include <linux/types.h>
 #include <asm/byteorder.h>