Add HierarchicalFlag & hierarchical_level_plus1 for AV1e.

Signed-off-by: Cheng, Rachel <rachel.cheng@intel.com>

va/va_enc_av1.h

diff --git a/va/va_enc_av1.h b/va/va_enc_av1.h
index 6a845b7..e162c0a 100644
--- a/va/va_enc_av1.h
+++ b/va/va_enc_av1.h
@@ -249,7 +249,10 @@
      */
     uint8_t     seq_tier;
 
-    uint8_t     reserved8b;
+    /** \brief Indicates whether or not the encoding is in dyadic hierarchical GOP structure.
+     *  value range [0..1].
+     */
+    uint8_t    HierarchicalFlag; 
 
     /** \brief Period between intra_only frames. */
     uint32_t    intra_period;
@@ -581,7 +584,11 @@
      */
     uint8_t     ref_frame_idx[7];
 
-    uint8_t     reserved8bits0;
+    /** \brief When hierarchical_level_plus1 > 0, hierarchical_level_plus1-1 indicates
+     *  the current frame's level. If VAEncMiscParameterTemporalLayerStructure
+     *  is valid (number_of_layers >0), hierarchical_level_plus1 shouldn't larger than number_of_layers.
+     */
+    uint8_t     hierarchical_level_plus1;
 
     /** \brief primary reference frame.
      *  Index into reference_frames[]