GN: use the correct fontconfig font mugger.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2202733002

Review-Url: https://codereview.chromium.org/2202733002
diff --git a/BUILD.gn b/BUILD.gn
index 8bf9d66..a310e33 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -257,12 +257,12 @@
       "third_party:freetype2",
     ]
     sources += [
-      "src/fonts/SkFontMgr_fontconfig.cpp",
       "src/ports/SkFontConfigInterface_direct.cpp",
       "src/ports/SkFontConfigInterface_direct_factory.cpp",
       "src/ports/SkFontHost_FreeType.cpp",
       "src/ports/SkFontHost_FreeType_common.cpp",
-      "src/ports/SkFontHost_fontconfig.cpp",
+      "src/ports/SkFontMgr_fontconfig.cpp",
+      "src/ports/SkFontMgr_fontconfig_factory.cpp",
     ]
   }