platform/chrome: cros_ec_typec: Set Pin Assignment E in DP PORT VDO

platform/chrome: cros_ec_typec: Set Pin Assignment E in DP PORT VDO

Pin C and D are used on C-to-C cable applications including docks,
and for USB-C adapters that convert from DP over USB-C to other
video standards.

Pin Assignment E is intended to be used with adapter from USB-C to DP
plugs or receptacles.

All Chromebook USB-C DFPs support DisplayPort Alternate Mode as the DP
Source with support for all 3 pin assignments. Pin Assignment E is required
in order to support if the user attaches a Pin E C-to-DP cable.

Without this, the displayport.c alt mode driver will error out of
dp_altmode_probe with an -ENODEV, as it cannot find a compatible matching
pin assignment between the DFP_D and UFP_D.

Fixes: dbb3fc0ffa95 ("platform/chrome: cros_ec_typec: Displayport support")
Signed-off-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Jameson Thies <jthies@google.com>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Link: https://lore.kernel.org/r/20250428174828.13939-1-bleung@chromium.org
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>