move cmake install out of advanced

Modules/CMakeSystemSpecificInformation.cmake

@@ -261,8 +261,6 @@ CMAKE_EXE_LINKER_FLAGS_MINSIZEREL
 CMAKE_EXE_LINKER_FLAGS_RELEASE
 CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO
 
-CMAKE_INSTALL_PREFIX
-
 CMAKE_SHARED_LINKER_FLAGS
 CMAKE_SHARED_LINKER_FLAGS_DEBUG
 CMAKE_SHARED_LINKER_FLAGS_MINSIZEREL
@@ -276,4 +274,8 @@ CMAKE_MODULE_LINKER_FLAGS_RELEASE
 CMAKE_MODULE_LINKER_FLAGS_RELWITHDEBINFO
 
 )
+IF(NOT UNIX)
+  MARK_AS_ADVANCED(CMAKE_INSTALL_PREFIX)
+ENDIF(NOT UNIX)
+
 SET(CMAKE_SYSTEM_SPECIFIC_INFORMATION_LOADED 1)