drm/i915/debugfs: pass intel_connector to intel_connector_debugfs_add()

Prefer the intel_ types. No functional changes.

v2: Fix build.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210830140222.12228-1-jani.nikula@intel.com