drm/i915/pps: move pps debugfs file to intel_pps.c

Continue with placing debugfs next to the implementation.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240408094357.3085319-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
3 files changed