zephyr test: Initialize partner VCONN role
zephyr test: Initialize partner VCONN role

After a Hard Reset and when initializing a PD partner emulator
structure, set the VCONN role to be consistent with the power role.

BUG=none
TEST=twister -T zephyr/test
BRANCH=none

Signed-off-by: Abe Levkoy <2e1ad7039298f93262cf06bbb457275fb3e2ecb5@chromium.org>
Change-Id: I6545d5febbbf6cd66fc8b9f17b5a3310f31772c7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3949572
Code-Coverage: Zoss <345cf107e82c70959d46f59d98bddc98ce458aff@prod.google.com>
Reviewed-by: Tomasz Michalec <c064a6042954d4ba0805003dc021b76413ff1548@google.com>

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