mediatek/mt8173: Add a stub implementation of the MT8173 SoC

BUG=chrome-os-partner:36682
TEST=emerge-oak coreboot
BRANCH=none

Change-Id: I748752d5abca813a0469d3a76e4d40fcbeb9b959
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: ece2f412d94f071a6f5f1dbed4dfaea504da9e1a
Original-Change-Id: I1dd5567a10d20840313703cfcd328bec591b4941
Original-Signed-off-by: Yidi Lin <yidi.lin@mediatek.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/292558
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/12587
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/soc/mediatek/mt8173/cbmem.c b/src/soc/mediatek/mt8173/cbmem.c
new file mode 100644
index 0000000..9a8ae7c
--- /dev/null
+++ b/src/soc/mediatek/mt8173/cbmem.c
@@ -0,0 +1,27 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 MediaTek 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.
+ *
+ * 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
+ */
+
+#include <cbmem.h>
+#include <stddef.h>
+#include <symbols.h>
+
+void *cbmem_top(void)
+{
+	return (void *)((uintptr_t) _dram + (CONFIG_DRAM_SIZE_MB << 20));
+}