drm/i915/panelreplay: Debugfs support for panel replay

Add debugfs support which will print source and sink status
per connector basis. Existing i915_psr_status and
i915_psr_sink_status will be used to get the source and
sink status of panel replay.

v1: Initial version. [rb-ed by Arun]
v2: Added check for DP 2.0 and connector type in connector_debugfs_add().
v3: Optimization and cosmetic changes. [Jouni]

Cc: Jouni Högander <jouni.hogander@intel.com>
Cc: Arun R Murthy <arun.r.murthy@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108072303.3414118-7-animesh.manna@intel.com