Enable newly created mlp option with -Dall=ON

Author: amadio

cmake/modules/RootBuildOptions.cmake

@@ -220,6 +220,7 @@ if(all)
  set(mathmore_defvalue ON)
  set(memstat_defvalue ON)
  set(minuit2_defvalue ON)
+ set(mlp_defvalue ON)
  set(monalisa_defvalue ON)
  set(mysql_defvalue ON)
  set(odbc_defvalue ON)