TCPMv2: TBT cable entry/exit should be symmetrical
TCPMv2: TBT cable entry/exit should be symmetrical

If SOP'/SOP'' enters TBT alt mode; then the code should have exit
logic for SOP'/SOP'' too. With LRD cable, there is SOP' enter mode, but
no SOP' exit mode.

The LRD cable SOP' exit mode logic is added.
Also only check SOP'' field in the active cable identity VDO when
the cable reports it's active.

BUG=none
BRANCH=none
TEST=on Brya, connect TBT dock with LRD cable, SOP' exit mode is sent
when exit TBT alt mode.

Signed-off-by: Li Feng <0fd15d95d647a38d004d7ac9a3d0587bb1c98551@intel.com>
Change-Id: Idef5a381ea3b51b4b5a5e102bd321eb8fb87dca4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3746291
Reviewed-by: Abe Levkoy <2e1ad7039298f93262cf06bbb457275fb3e2ecb5@chromium.org>
Commit-Queue: Keith Short <f6d578f97033c25f1206cb57d52f358974c82954@chromium.org>
Reviewed-by: Vijay P Hiremath <006c712879a3af08bfdb5c2b8491a8b2d5fd73cd@intel.com>

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