drm/i915/whl: Introducing Whiskey Lake platform

Whiskey Lake uses the same gen graphics as Coffe Lake, including some
ids that were previously marked as reserved on Coffe Lake, but that
now are moved to WHL page.

So, let's just move them to WHL macros that will feed into CFL macro
just to keep it better organized to make easier future code review
but it will be handled as a CFL.

v2:
Fixing GT level of some ids

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180614233720.30517-1-jose.souza@intel.com