CMake: mark package variables as advanced

Silence pkg_check_modules message.

build/cmake/modules/FindFontconfig.cmake

@@ -43,7 +43,7 @@ else (FONTCONFIG_LIBRARIES AND FONTCONFIG_INCLUDE_DIR)
     # use pkg-config to get the directories and then use these values
     # in the FIND_PATH() and FIND_LIBRARY() calls
     find_package(PkgConfig)
-    pkg_check_modules(PC_FONTCONFIG fontconfig)
+    pkg_check_modules(PC_FONTCONFIG QUIET fontconfig)
 
     set(FONTCONFIG_DEFINITIONS ${PC_FONTCONFIG_CFLAGS_OTHER})
   endif (NOT WIN32)