kms: Add MetaKmsMode abstraction

This contains a copy of a drmModeModeInfo, describing a mode. It also
has an unused pointer to the impl device it is associated with. It'll
later be used to get a blob ID for the mode.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1488>

src/backends/native/meta-kms-mode-private.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2020 Red Hat
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#ifndef META_KMS_MODE_PRIVATE_H
+#define META_KMS_MODE_PRIVATE_H
+
+#include "backends/native/meta-kms-mode.h"
+
+void meta_kms_mode_free (MetaKmsMode *mode);
+
+MetaKmsMode * meta_kms_mode_new (MetaKmsImplDevice     *impl_device,
+                                 const drmModeModeInfo *drm_mode);
+
+#endif /* META_KMS_MODE_PRIVATE_H */