drm/xe/display: Drop unnecessary xe_gt.h includes

None of the Xe display files work directly with the GT or need anything
from xe_gt.h.  Drop the unnecessary include.

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240829230307.886233-2-matthew.d.roper@intel.com