drm/amd/display: Further fix of psr eDP p-state warning

[Why]
psr doesn't get fully disabled before hitting hubbub1_wm_change_req_wa.

[How]
Pass TRUE to "wait" parameter to get psr fully disabled.

Follow-Up fix to:
dc: PSR eDP p-state warning occurs intermittently after unplug DP

Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>