USB PD: Only maintain contracts over sysjump when sinking
USB PD: Only maintain contracts over sysjump when sinking

Currently, the pd_task will attempt to maintain both source and sink
contracts after an unlocked sysjump or unlocked EC reset.  However, the
pd_task will disable Vbus to any partners it was sourcing, causing the
soft reset process to lead to a hard reset and disconnection.

Since the port partner will be without Vbus and unable to respond, treat
the contract as terminated and the port as the default state.

BUG=b:132110509
BRANCH=octopus
TEST=unlocked sysjumps with a display port dongle and hoho to ensure
they were treated as disconnected, unlocked sysjumps with charger to
ensure it was soft reset

Change-Id: Ie477f393ea828a4e880c8e8ccbe72539e8be721a
Signed-off-by: Diana Z <cb2016afc7183e5356c690dc63b4ba817470501a@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1639212
Reviewed-by: Jett Rink <9d4aef0593e6843318d99df31597fb6153b89787@chromium.org>
Reviewed-by: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>

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