Enable txmg by default (fix HBD/LBD mismatch)

BUG=aomedia:39

Change-Id: I89858a8a26547fea4a9d37855a28c0098273316f
diff --git a/build/cmake/aom_config_defaults.cmake b/build/cmake/aom_config_defaults.cmake
index 2fc8c11..2755ff7 100644
--- a/build/cmake/aom_config_defaults.cmake
+++ b/build/cmake/aom_config_defaults.cmake
@@ -203,7 +203,7 @@
 set(CONFIG_TRIPRED 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_TX64X64 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_TXK_SEL 0 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_TXMG 0 CACHE NUMBER "AV1 experiment flag.")
+set(CONFIG_TXMG 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_UNPOISON_PARTITION_CTX 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_VAR_REFS 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_VAR_TX 1 CACHE NUMBER "AV1 experiment flag.")
diff --git a/configure b/configure
index 1a94589..7e47ced 100755
--- a/configure
+++ b/configure
@@ -521,6 +521,7 @@
     soft_enable ext_delta_q
     soft_enable loopfiltering_across_tiles
     soft_enable var_tx
+    soft_enable txmg
     soft_enable ext_inter
     soft_enable wedge
     soft_enable compound_segment