drm/amd/display: Don't use fsleep for PSR exit waits on dmub replay

[Why]
These functions can be called from high IRQ levels and the OS will hang
if it tries to use a usleep_highres or a msleep.

[How]
Replace the flseep with a udelay for dmub_replay_enable.
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dce/dmub_replay.c

@@ -96,7 +96,8 @@ static void dmub_replay_enable(struct dmub_replay *dmub, bool enable, bool wait,
 					break;
 			}
 
-			fsleep(500);
+			/* must *not* be fsleep - this can be called from high irq levels */
+			udelay(500);
 		}
 
 		/* assert if max retry hit */