drm/i915/display: Convert intel_pch towards intel_display

Now that intel_pch lives under display, let's begin its
conversion towards struct intel_display.

Move the pch_type to inside intel_display and convert the
callers.

While doing it, sort intel_display_core.h include list
alphabetically.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://lore.kernel.org/r/8ffe86eb2a02153e3f866a81fb6dc8a3327a0f25.1744364975.git.jani.nikula@intel.com


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