drm/xe: remove compat i915_drv.h and -Ddrm_i915_private=xe_device hack
The xe display build no longer needs the compat i915_drv.h or the ugly
-Ddrm_i915_private=xe_device hack. Remove them, with great pleasure.
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patch.msgid.link/8d2da5404439ed334d7682922b599f36eeb60e9d.1767009044.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>