drm/amd/display: Refactor Replay functionality into dedicated power_replay module

drm/amd/display: Refactor Replay functionality into dedicated power_replay module

[Why]
Extract all Replay related functions from power.c and
power_helpers.c into a new power_replay.c module for
better code organization and maintainability.

[How]
Create new power_replay.c file containing
Replay-related functions moved from power.c
and power_helpers.c . Update mod_power.h with
function declarations. Maintain forward
declaration for type compatibility.

Reviewed-by: Robin Chen <robin.chen@amd.com>
Signed-off-by: Lohita Mudimela <lohita.mudimela@amd.com>
Signed-off-by: Ivan Lipski <ivan.lipski@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>