vboot_reference: Rename Cr50 to GSC when applicable

Recent ChromeOS devices use Ti50 instead of Cr50. Therefore, some
strings or comments are not accurate anymore. When applicable, rename
Cr50 to GSC (Google security chip). The only functional change in this
patch is the recovery reason string for 0x63, which is changed from

 Failed to get boot mode from Cr50

to

 Failed to get boot mode from GSC

Also deprecate the old enum VB2_RECOVERY_CR50_BOOT_MODE. It will be
removed once coreboot switches to the new name.

BUG=b:275544927
TEST=make runtests -j
BRANCH=none

Change-Id: I1a5b25b832b35fa52f50d8c858468527a28d0105
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/4756700
Reviewed-by: Yidi Lin <yidilin@chromium.org>
6 files changed