asrock/b75pro3-m: Add superio ACPI declarations

Without it the PS/2 keyboard doesn't work after booting into the OS.

Change-Id: Idcb0ea0779fcd5dfd6e0fbf33a532ecf0caec420
Signed-off-by: Iru Cai <mytbk920423@gmail.com>
Reviewed-on: https://review.coreboot.org/26131
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/mainboard/asrock/b75pro3-m/acpi/superio.asl

@@ -0,0 +1,26 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2016 secunet Security Networks AG
+ * Copyright (C) 2017 Tobias Diedrich <ranma+coreboot@tdiedrich.de>
+ * Copyright (C) 2018 Iru Cai <mytbk920423@gmail.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; version 2 of the License.
+ *
+ * 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.
+ */
+
+#undef SUPERIO_DEV
+#undef SUPERIO_PNP_BASE
+#define SUPERIO_DEV		SIO0
+#define SUPERIO_PNP_BASE	0x2e
+
+#define NCT6776_SHOW_SP1	1
+#define NCT6776_SHOW_KBC	1
+
+#include "superio/nuvoton/nct6776/acpi/superio.asl"