superio/winbond/*: Provide common romstage component

Following the reasoning of:
cf7b498 superio/fintek/*: Factor out generic romstage component

Change-Id: I3e889c0305c012e7556a5dd348e7f1e1ba629a9d
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/5587
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/superio/winbond/common/winbond.h

@@ -0,0 +1,29 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 Edward O'Callaghan <eocallaghan@alterapraxis.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef SUPERIO_WINBOND_COMMON_ROMSTAGE_H
+#define SUPERIO_WINBOND_COMMON_ROMSTAGE_H
+
+#include <arch/io.h>
+#include <stdint.h>
+
+void winbond_enable_serial(device_t dev, u16 iobase);
+
+#endif /* SUPERIO_WINBOND_COMMON_ROMSTAGE_H */