Remove CONFIG_EXT_PARTITION config flag from cmake defaults

Change-Id: Ia43c427663437098f7eb9c32f336b4732203b90b
diff --git a/build/cmake/aom_config_defaults.cmake b/build/cmake/aom_config_defaults.cmake
index 33ed761..abece50 100644
--- a/build/cmake/aom_config_defaults.cmake
+++ b/build/cmake/aom_config_defaults.cmake
@@ -100,7 +100,6 @@
 set(CONFIG_EXT_DELTA_Q 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_EXT_INTRA_MOD 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_EXT_INTRA_MOD2 1 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_EXT_PARTITION 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_EXT_PARTITION_TYPES 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_EXT_TILE 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_EXT_WARPED_MOTION 1 CACHE NUMBER "AV1 experiment flag.")