drm/amd/display: Fix prefetch calculations for dcn32

[Description]
Prefetch calculation loop was not exiting until utilizing all of vstartup if it
failed once.  Locals need to be reset on each iteration of the loop.

Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Dillon Varone <Dillon.Varone@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>

drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.c

@@ -718,6 +718,8 @@ static void DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndPerforman
 
 	do {
 		MaxTotalRDBandwidth = 0;
+		DestinationLineTimesForPrefetchLessThan2 = false;
+		VRatioPrefetchMoreThanMax = false;
 #ifdef __DML_VBA_DEBUG__
 		dml_print("DML::%s: Start loop: VStartup = %d\n", __func__, mode_lib->vba.VStartupLines);
 #endif