drm/i915/pch: move PCH detection to intel_display_driver_early_probe()

Make PCH detection part of display. For now, call it also for
!HAS_DISPLAY() to avoid functional changes here.

Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/de70b35b170c9a74edddb497a209eb10427b77de.1744364975.git.jani.nikula@intel.com


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