auron*: Add mosys platform version support

Check the SMBIOS table for mainboard version.

BUG=chrome-os-partner:39245
BRANCH=none
TEST=mosys platform version matches dmidecode mainboard version string.

Change-Id: I6772321005cd6756475cd2cc93128934f2fb8c0c
Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Reviewed-on: https://chromium-review.googlesource.com/266392
Reviewed-by: Shawn N <shawnn@chromium.org>
(cherry picked from commit 283f65c12a44696eed391abdc4b389b28adb2ea7)
Reviewed-on: https://chromium-review.googlesource.com/267640
Reviewed-by: David Hendricks <dhendrix@chromium.org>
diff --git a/platform/google/auron/sys.c b/platform/google/auron/sys.c
index d00af2f..fdcf3e3 100644
--- a/platform/google/auron/sys.c
+++ b/platform/google/auron/sys.c
@@ -33,6 +33,15 @@
 #include "mosys/platform.h"
 
 #include "lib/smbios.h"
+#include "drivers/google/cros_ec.h"
+
+static const char *auron_get_version(struct platform_intf *intf)
+{
+	if (intf->cb && intf->cb->smbios)
+		return intf->cb->smbios->system_version(intf);
+	else
+		return NULL;
+}
 
 static const char *auron_get_vendor(struct platform_intf *intf)
 {
@@ -68,4 +77,5 @@
 	.name			= &auron_get_name,
 	.family			= &auron_get_family,
 	.firmware_vendor	= &auron_get_firmware_vendor,
+	.version		= &auron_get_version,
 };