esp_lcd: Add function for register on color done callback.

components/esp_lcd/interface/esp_lcd_panel_io_interface.h

@@ -7,6 +7,7 @@
 
 #include <stdbool.h>
 #include "esp_err.h"
+#include "esp_lcd_panel_io.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -73,6 +74,18 @@ struct esp_lcd_panel_io_t {
      *          - ESP_OK                on success
      */
     esp_err_t (*del)(esp_lcd_panel_io_t *io);
+
+    /**
+     * @brief Register LCD panel IO callbacks
+     *
+     * @param[in] io LCD panel IO handle, which is created by factory API like `esp_lcd_new_panel_io_spi()`
+     * @param[in] cbs structure with all LCD panel IO callbacks
+     * @param[in] user_ctx User private data, passed directly to callback's user_ctx
+     * @return
+     *          - ESP_ERR_INVALID_ARG   if parameter is invalid
+     *          - ESP_OK                on success
+     */
+    esp_err_t (*register_event_callbacks)(esp_lcd_panel_io_t *io, const esp_lcd_panel_io_callbacks_t *cbs, void *user_ctx);
 };
 
 #ifdef __cplusplus