drm/xe: Refactor PAT dump to use shared helpers

drm/xe: Refactor PAT dump to use shared helpers

Move the PAT entry formatting into shared helper functions to ensure
consistency and enable code reuse.

This preparation is necessary for a follow-up patch that introduces a
software-based PAT dump, which is required for debugging on VFs where
hardware access is limited.

V2: (Matt)
- Xe3p XPC doesn’t define COMP_EN; omit it to match bspec and avoid
confusion.

Suggested-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Xin Wang <x.wang@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patch.msgid.link/20251205070220.27859-1-x.wang@intel.com