usb: typec: altmodes/displayport: Use proper macro for pin assignment check

usb: typec: altmodes/displayport: Use proper macro for pin assignment check

While looking at the DP configuration VDO to determine the peripheral
configuration, the spec (Table 8-5: DisplayPort Configurations, VESA
DisplayPort Alt Mode Standard v2.0) lists the options as "UFP_U as a DP
Source/Sink Device".

So, use the correct macro while performing this check. Effectively it's
the same as the existing code, but the proposed macro describes the
state a little better.

No functional changes introduced.

Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20230111020546.3384569-3-pmalani@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>