mb/google/volteer: Create volet variant

Create the volet variant of the volteer reference board by copying
the template files to a new directory named for the variant.

(Auto-Generated by create_coreboot_variant.sh version 4.5.0).

BUG=b:186334008
BRANCH=None
TEST=util/abuild/abuild -p none -t google/volteer -x -a
make sure the build includes GOOGLE_VOLET

Signed-off-by: Sheng-Liang Pan <sheng-liang.pan@quanta.corp-partner.google.com>
Change-Id: Ic6ca9a78494e3819b0fb39c0bcc70fed95c2c589
Reviewed-on: https://review.coreboot.org/c/coreboot/+/52871
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: YH Lin <yueherngl@google.com>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
diff --git a/src/mainboard/google/volteer/variants/volet/overridetree.cb b/src/mainboard/google/volteer/variants/volet/overridetree.cb
new file mode 100644
index 0000000..32204c5
--- /dev/null
+++ b/src/mainboard/google/volteer/variants/volet/overridetree.cb
@@ -0,0 +1,6 @@
+chip soc/intel/tigerlake
+
+	device domain 0 on
+	end
+
+end