drm/amd/display: Add regkey for DRR control for internal panel

Also need to change default to off

Signed-off-by: Anthony Koo <[email protected]>
Reviewed-by: Tony Cheng <[email protected]>
Acked-by: Harry Wentland <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
3 files changed