drm/dp: Add DPCD for configuring AS SDP for PR + VRR

drm/dp: Add DPCD for configuring AS SDP for PR + VRR

Add additional DPCDs required to be configured to support VRR with Panel
Replay. These DPCDs are specifically required for configuring Adaptive Sync
SDP and are introduced in DP v2.1.

v2:
 - Correct the shift for the bits. (Ville)
 - Add DP_PR_ prefix for the PR-related fields.
v3:
 - Use macro values in their shifted form to match the convention. (Ville)
v4:
 - Add macro for the mask. (Ville)

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/20260428074457.3566918-5-ankit.k.nautiyal@intel.com