env: Drop common init() functions

Most of the init() implementations just use the default environment.
Adjust env_init_new() to do this automatically, and drop the redundant
code.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>

env/remote.c

@@ -33,9 +33,7 @@ static int env_remote_init(void)
 		return 0;
 	}
 
-	gd->env_addr = (ulong)default_environment;
-	gd->env_valid = 0;
-	return 0;
+	return -ENOENT;
 }
 
 #ifdef CONFIG_CMD_SAVEENV