Update vboot submodule to upstream master

Updating from commit id e0b38418:
- image_signing: Add sha1sum of keys in keyset to VERSION.signer.

To commit id 392211f0:
- Update Android signing to support signature scheme v2

This fixes bulding with depthcharge master.

Change-Id: I07b570f54b26a937a5a7c53ade464e0c7a550312
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://review.coreboot.org/25837
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

3rdparty/vboot

@@ -1 +1 @@
-Subproject commit e0b3841863281a3fc3b188bfbab55d401fabdc73
+Subproject commit 392211f0358919d510179ad399d8f056180e652e