Move libdrm target behind conditional

ui/ozone/platform/dri/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/linux/pkg_config.gni")
 import("//ui/ozone/ozone.gni")
 
+pkg_config("libdrm") {
+  packages = [ "libdrm" ]
+}
+
 source_set("dri_common") {
   sources = [
     "chromeos/display_mode_dri.cc",
     "chromeos/display_mode_dri.h",
     "chromeos/display_snapshot_dri.cc",
     "chromeos/display_snapshot_dri.h",
     "chromeos/native_display_delegate_dri.cc",
     "chromeos/native_display_delegate_dri.h",
     "cursor_factory_evdev_dri.cc",
     "cursor_factory_evdev_dri.h",
@@ skipping 30 matching lines @@
     "//ipc",
     "//ui/base",
     "//ui/display/types",
     "//ui/events",
     "//ui/events/ozone:events_ozone_evdev",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
 
   direct_dependent_configs = [
-    "//build/config/linux:libdrm",
+    ":libdrm",
   ]
 }
 
 if (ozone_platform_dri) {
   source_set("dri") {
     sources = [
       "ozone_platform_dri.cc",
       "ozone_platform_dri.h",
     ]
 
@@ skipping 57 matching lines @@
       "//base",
       "//skia",
       "//ui/events/ozone:events_ozone_evdev",
     ]
 
     direct_dependent_configs = [
       ":libgbm",
     ]
   }
 }