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

ui/ozone/platform/drm/drm.gypi

 # 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.
 
 {
   'variables': {
     'internal_ozone_platform_deps': [
       'ozone_platform_drm',
     ],
     'internal_ozone_platform_unittest_deps': [
       'ozone_platform_drm_unittests',
     ],
     'internal_ozone_platforms': [
       'dri',
+      'drm',
     ],
   },
   'targets': [
     {
       'target_name': 'ozone_platform_drm',
       'type': 'static_library',
       'dependencies': [
         '../../base/base.gyp:base',
         '../../build/linux/system.gyp:libdrm',
         '../../skia/skia.gyp:skia',
@@ skipping 99 matching lines @@
           'gpu/hardware_display_controller_unittest.cc',
           'gpu/hardware_display_plane_manager_unittest.cc',
           'gpu/screen_manager_unittest.cc',
           'test/mock_drm_device.cc',
           'test/mock_drm_device.h',
         ],
       },
     },
   ],
 }