According to patch "drm/i915/aml: Introducing Amber Lake platform"
(e3646724). Add a new marco for AML ULX GT2 devices.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jose Roberto de Souza <jose.souza@intel.com>
Signed-off-by: NLee, Shawn C <shawn.c.lee@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1538034499-31256-1-git-send-email-shawn.c.lee@intel.com