soc/intel/common/sa: Remove EBDA dependency

Saving cbmem_top across stages is not needed anymore so EBDA should
not be used. The guard to cbmem_top_chipset implementation was
inappropriate.

Change-Id: Ibbb3534b88de4f7b6fc39675a77461265605e56e
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36614
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Michael Niewöhner
diff --git a/src/soc/intel/common/block/systemagent/cbmem.c b/src/soc/intel/common/block/systemagent/cbmem.c
new file mode 100644
index 0000000..7e743df
--- /dev/null
+++ b/src/soc/intel/common/block/systemagent/cbmem.c
@@ -0,0 +1,23 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * 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 <cbmem.h>
+#include <fsp/util.h>
+
+void *cbmem_top_chipset(void)
+{
+	struct range_entry tolum;
+
+	fsp_find_bootloader_tolum(&tolum);
+	return (void *)(uintptr_t)range_entry_end(&tolum);
+}