drm/xe/pcode: add struct drm_device based interface

In preparation for dropping the dependency on struct intel_uncore or
struct xe_tile from display code, add a struct drm_device based
interface to pcode.

Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://lore.kernel.org/r/eeaa9cc8438caab2e22f9cb2142fbc18cc0fd861.1750678991.git.jani.nikula@intel.com


Signed-off-by: Jani Nikula <jani.nikula@intel.com>