chromeos-cr50: uprev pre-pvt to version 0.6.9

The new pre-pvt image incorporates the following
fixes/improvements/new features:

- change TRNG_EMPTY_COUNT to 0x7ff
- Add debug message for detachable cutoff
- suppress TPM_STS messages
- add get apro hash vendor command

The new version string is
Build:   0.6.9/cr50_v1.9308_B.941-ef244e460
         tpm2:v1.9308_26_0.60-a2ed29c
         cryptoc:v1.9308_26_0.5-b941bbe
         2021-02-02 23:37:47 @chromeos-ci-factory-us-central2-c

BUG=b:179153941,b:180946475
TEST='sudo emerge chroemos-cr50' brings in the new version into
      /opt/google/firmware/cr50/cr50.bin.prepvt

Change-Id: I253a9156e9e44c92322a7399459d6ee47860dde1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2713728
Tested-by: Mary Ruthven <mruthven@chromium.org>
Reviewed-by: Andrey Pronin <apronin@chromium.org>
Commit-Queue: Mary Ruthven <mruthven@chromium.org>
(cherry picked from commit 6f4b8071a90d256d7f1ebf8674c488b6cc97fe49)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2772387
Reviewed-by: Mary Ruthven <mruthven@chromium.org>
Commit-Queue: Shiva Sai Kothapalli <kshivasai@google.com>
Tested-by: Shiva Sai Kothapalli <kshivasai@google.com>
3 files changed