Bugfix for SDP when multiple tiles are applied

This commit fixes the bug when multiple-tile encoding are employed. tree_type is a super block level parameter, it can be luma_part or chroma_part or shared_part. When SDP is enabled, encoder will loop luma_part and chroma_part for each super block. But previously, this variable tree_type was mistakenly added to AV1_COMMON struct.

The compiling flag CONFIG_SDP is turned off by default in this CL.

Change-Id: Ia05424455fd7583a5eb059ead46dd55a4563452b
(cherry picked from commit 3af1f7b6353b81e2684e0496099c29938f4eab1f)
diff --git a/av1/encoder/segmentation.c b/av1/encoder/segmentation.c
index daa62f5..a240b59 100644
--- a/av1/encoder/segmentation.c
+++ b/av1/encoder/segmentation.c
@@ -108,7 +108,12 @@
   if (bsize == BLOCK_8X8)
     partition = PARTITION_NONE;
   else
+#if CONFIG_SDP
+    partition =
+        get_partition(cm, xd->tree_type == CHROMA_PART, mi_row, mi_col, bsize);
+#else
     partition = get_partition(cm, mi_row, mi_col, bsize);
+#endif
   switch (partition) {
     case PARTITION_NONE: CSEGS(bs, bs, 0, 0); break;
     case PARTITION_HORZ: