net: Move MAC-seeded rand out of bootp.c

Make the MAC-seeded random number generator available to /net in
general.  MAC-seeded rand will be needed by link-local as well, so
give it an interface.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Simon Glass <sjg@chromium.org>

net/net_rand.h

@@ -0,0 +1,26 @@
+/*
+ *	Copied from LiMon - BOOTP.
+ *
+ *	Copyright 1994, 1995, 2000 Neil Russell.
+ *	(See License)
+ *	Copyright 2000 Paolo Scaffardi
+ */
+
+#ifndef __NET_RAND_H__
+#define __NET_RAND_H__
+
+#define RAND_MAX 0xffffffff
+
+/*
+ * Seed the random number generator using the eth0 MAC address
+ */
+void srand_mac(void);
+
+/*
+ * Get a random number (after seeding with MAC address)
+ *
+ * @return random number
+ */
+unsigned long rand(void);
+
+#endif /* __NET_RAND_H__ */