Exynos 5420: Enable dynamic CBMEM

...  In order to do this, the graphics memory has to move into
the resource allocator and out of CBMEM.

Change-Id: I565c3d6dea747822fbabf6f3845232d4adfbf333
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: https://gerrit.chromium.org/gerrit/63657
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/4391
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
diff --git a/src/cpu/samsung/exynos5420/cbmem.c b/src/cpu/samsung/exynos5420/cbmem.c
new file mode 100644
index 0000000..e77af99
--- /dev/null
+++ b/src/cpu/samsung/exynos5420/cbmem.c
@@ -0,0 +1,28 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2013 Google 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 <stddef.h>
+#include <cbmem.h>
+#include "cpu.h"
+
+void *cbmem_top(void)
+{
+	return (void *)(get_fb_base_kb() * KiB);
+}
+