[Encode] Use re-PAK threshold for quality

Default TU (TU4) settings were used for TU2, which is a quality mode
diff --git a/media_driver/agnostic/common/codec/hal/codechal_vdenc_vp9_base.cpp b/media_driver/agnostic/common/codec/hal/codechal_vdenc_vp9_base.cpp
index 7e769b9..bef20eb 100644
--- a/media_driver/agnostic/common/codec/hal/codechal_vdenc_vp9_base.cpp
+++ b/media_driver/agnostic/common/codec/hal/codechal_vdenc_vp9_base.cpp
@@ -568,6 +568,7 @@
         switch (m_vp9SeqParams->TargetUsage)
         {
         case TU_QUALITY:
+        case 2: 
             repakSavingThreshold = 2;
             break;
         case TU_PERFORMANCE: