cmake deps problem : CONFIG_TXMG & HIGHBITDEPTH

HighBitdepth should be turned on if TXMG is turned on.

Change-Id: If5295d664dce17b7856b8cd675f84d915f25c33d
diff --git a/build/cmake/aom_experiment_deps.cmake b/build/cmake/aom_experiment_deps.cmake
index 7480ceb..13f8f2b 100644
--- a/build/cmake/aom_experiment_deps.cmake
+++ b/build/cmake/aom_experiment_deps.cmake
@@ -157,6 +157,13 @@
       change_config_and_warn(CONFIG_LV_MAP 1 CONFIG_TXK_SEL)
     endif ()
   endif ()
+
+  if (CONFIG_TXMG)
+    if (NOT CONFIG_HIGHBITDEPTH)
+      change_config_and_warn(CONFIG_HIGHBITDEPTH 1 CONFIG_TXMG)
+    endif ()
+  endif ()
+
 endmacro ()
 
 endif ()  # AOM_BUILD_CMAKE_AOM_EXPERIMENT_DEPS_CMAKE_