drm/connector: Introduce a TV margins structure

The TV margins has been defined as a structure inside the
drm_connector_state structure so far. However, we will need it in other
structures as well, so let's move that structure definition so that it can
be reused.
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/38b773b03f15ec7a135cdf8f7db669e5ada20cf2.1560783090.git-series.maxime.ripard@bootlin.com

include/drm/drm_connector.h

@@ -463,14 +463,38 @@ int drm_display_info_set_bus_formats(struct drm_display_info *info,
 				     const u32 *formats,
 				     unsigned int num_formats);
 
+/**
+ * struct drm_connector_tv_margins - TV connector related margins
+ *
+ * Describes the margins in pixels to put around the image on TV
+ * connectors to deal with overscan.
+ */
+struct drm_connector_tv_margins {
+	/**
+	 * @bottom: Bottom margin in pixels.
+	 */
+	unsigned int bottom;
+
+	/**
+	 * @left: Left margin in pixels.
+	 */
+	unsigned int left;
+
+	/**
+	 * @right: Right margin in pixels.
+	 */
+	unsigned int right;
+
+	/**
+	 * @top: Top margin in pixels.
+	 */
+	unsigned int top;
+};
+
 /**
  * struct drm_tv_connector_state - TV connector related states
  * @subconnector: selected subconnector
- * @margins: margins (all margins are expressed in pixels)
- * @margins.left: left margin
- * @margins.right: right margin
- * @margins.top: top margin
- * @margins.bottom: bottom margin
+ * @margins: TV margins
  * @mode: TV mode
  * @brightness: brightness in percent
  * @contrast: contrast in percent
@@ -481,12 +505,7 @@ int drm_display_info_set_bus_formats(struct drm_display_info *info,
  */
 struct drm_tv_connector_state {
 	enum drm_mode_subconnector subconnector;
-	struct {
-		unsigned int left;
-		unsigned int right;
-		unsigned int top;
-		unsigned int bottom;
-	} margins;
+	struct drm_connector_tv_margins margins;
 	unsigned int mode;
 	unsigned int brightness;
 	unsigned int contrast;