google/purin: add DMA coherent region

BUG=none
BRANCH=broadcom-firmware
TEST=boot to depthcharge

Change-Id: Id10437c12e219e07121395abd442d53b3b56c7be
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: f33e9218ca8df1d149761c09253c30837b607433
Original-Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Original-Reviewed-on: https://chrome-internal-review.googlesource.com/204757
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Original-Commit-Queue: Daisuke Nojiri <dnojiri@google.com>
Original-Tested-by: Daisuke Nojiri <dnojiri@google.com>
Original-Change-Id: I93def9c326cc8b4fea69078987bddf09d9f2a797
Original-Reviewed-on: https://chromium-review.googlesource.com/256417
Reviewed-on: http://review.coreboot.org/9854
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/soc/broadcom/cygnus/sdram.c b/src/soc/broadcom/cygnus/sdram.c
index 1642842..bab126d 100644
--- a/src/soc/broadcom/cygnus/sdram.c
+++ b/src/soc/broadcom/cygnus/sdram.c
@@ -60,3 +60,8 @@
 
 	test_ddr();
 }
+
+uint32_t sdram_size_mb(void)
+{
+	return CONFIG_DRAM_SIZE_MB;
+}