autostart: unify duplicated logic into the bootm code

Rather than having a bunch of random commands handle autostart behavior,
unify the logic in a single place.  This also fixes building of these

different commands when bootm is disabled.

Acked-by: Matthew McClintock <msm@freescale.com>
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/common/cmd_net.c b/common/cmd_net.c
index 75ba1c3..872f4a6 100644
--- a/common/cmd_net.c
+++ b/common/cmd_net.c
@@ -227,17 +227,8 @@
 	/* flush cache */
 	flush_cache(load_addr, size);
 
-	/* Loading ok, check if we should attempt an auto-start */
-	if (((s = getenv("autostart")) != NULL) && (strcmp(s,"yes") == 0)) {
-		char *local_args[2];
-		local_args[0] = argv[0];
-		local_args[1] = NULL;
-
-		printf ("Automatic boot of image at addr 0x%08lX ...\n",
-			load_addr);
-		show_boot_progress (82);
-		rcode = do_bootm (cmdtp, 0, 1, local_args);
-	}
+	show_boot_progress(82);
+	rcode = bootm_maybe_autostart(cmdtp, argv[0]);
 
 	if (rcode < 0)
 		show_boot_progress (-83);