TCPMV2: Prevent EC boot loop when battery is dead
TCPMV2: Prevent EC boot loop when battery is dead

Transition to Unattached.SNK state when a dead battery
is detected on EC boot.

BUG=b:205883173
TEST=Verified that EC does not boot when battery is dead
BRANCH=main

Signed-off-by: Sam Hurst <500b4cddcd66abe3fe333e92c4c95d7f41e62e4e@google.org>
Change-Id: Ib49ed1f11a16da08909524180b825a8942116635
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3280648
Tested-by: Sam Hurst <500b4cddcd66abe3fe333e92c4c95d7f41e62e4e@google.com>
Reviewed-by: Diana Z <cb2016afc7183e5356c690dc63b4ba817470501a@chromium.org>
Reviewed-by: Keith Short <f6d578f97033c25f1206cb57d52f358974c82954@chromium.org>
Commit-Queue: Sam Hurst <500b4cddcd66abe3fe333e92c4c95d7f41e62e4e@google.com>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec