rockchip/rk3399: Add a stub implementation of the rk3399 SOC

Most things still need to be filled in, but this will allow
us to build boards which use this SOC.

BRANCH=none
BUG=chrome-os-partner:51537
TEST=with the rest of the patches applied Kevin board can be booted to
     Linux login propmt.

Change-Id: I6f2407ff578dcd3d0daed86dd03d8f5f4edcac53
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 27dfc39efe95025be2271e2e00e9df93b7907840
Original-Change-Id: I6f2407ff578dcd3d0daed86dd03d8f5f4edcac53
Original-Signed-off-by: huang lin <hl@rock-chips.com>
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/332385
Reviewed-on: https://review.coreboot.org/13915
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/src/soc/rockchip/rk3399/clock.c b/src/soc/rockchip/rk3399/clock.c
new file mode 100644
index 0000000..cb7b400
--- /dev/null
+++ b/src/soc/rockchip/rk3399/clock.c
@@ -0,0 +1,21 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Rockchip Inc.
+ *
+ * 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.
+ *
+ */
+
+#include <soc/clock.h>
+
+void rkclk_configure_spi(unsigned int bus, unsigned int hz)
+{
+}