[Ozone] Update GYP and GN to include a DRM platform

ui/ozone/platform/drm/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")
 
 declare_args() {
   use_mesa_platform_null = false
 }
@@ skipping 82 matching lines @@
     "//ui/events/ozone:events_ozone_evdev",
     "//ui/events/ozone:events_ozone_layout",
     "//ui/events/platform",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
 
   public_configs = [ ":libdrm" ]
 }
 
-if (ozone_platform_dri) {
+if (ozone_platform_dri || ozone_platform_drm) {
   source_set("drm") {
     sources = [
       "ozone_platform_drm.cc",
       "ozone_platform_drm.h",
     ]
 
     deps = [
       ":drm_common",
       "//base",
       "//skia",
@@ skipping 55 matching lines @@
       "//ui/events/ozone:events_ozone_layout",
     ]
 
     public_configs = [ ":libgbm" ]
 
     if (use_mesa_platform_null) {
       defines += [ "USE_MESA_PLATFORM_NULL" ]
     }
   }
 }