Update vboot submodule to upstream main

Updating from commit id 4423276b:
2021-08-31 17:41:34 +0000 - (crossystem: add a hwid override mechanism from chromeos-config)

to commit id c5a482ed:
2021-09-08 17:16:59 +0000 - (sign_official_build: disable gsetup for reven)

This brings in 10 new commits.

Signed-off-by: Hsuan Ting Chen <roccochen@chromium.org>
Change-Id: I67d4bfa182eae98bb23ae487f117c991502b66ed
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57639
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
diff --git a/3rdparty/vboot b/3rdparty/vboot
index 4423276..c5a482e 160000
--- a/3rdparty/vboot
+++ b/3rdparty/vboot
@@ -1 +1 @@
-Subproject commit 4423276b4607cf1b3975eaff57d17869c0620ecd
+Subproject commit c5a482edd53d705c8eb78eb1472eae2105d4c68f