Add structure representing Adaptive Sync Secondary Data Packet (AS SDP).
Also, add Adaptive Sync SDP logging in drm_dp_helper.c to facilitate
debugging.

--v2:
- Update logging. [Jani, Ankit]
- Use 'as_sdp' instead of 'async' [Ankit]
- Correct define placeholders to where they are actually used. [Jani]
- Update members in 'as_sdp' structure to make it uniform. [Jani]

--v3:
- Added changes to dri-devel mailing list. No code changes.

--v4:
- Instead of directly using operation mode, use an enum to accommodate
all operation modes (Ankit).

--v5:
Nit-pick changes to commit message.

--v6:
- Add correct place holder and name change for AS_SDP_OP_MODE.
- Separate i915 changes from drm changes.
- Remove extra lines.

--v7:
- Add drm/dp in subject line (Ankit)
Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240322031157.3823909-3-mitulkumar.ajitkumar.golani@intel.com