fix(esp_lvgl_port): remove IRAM_ATTR from forward declaration

Having IRAM_ATTR on both the forward declaration and the definition of
lvgl_port_flush_rgb_vsync_ready_callback caused conflicting section
attributes (.iram1.0 vs .iram1.1) at link time on some IDF versions.
The attribute on the definition is sufficient to place the function in
IRAM.

Author: matiasgibbons

components/esp_lvgl_port/src/lvgl9/esp_lvgl_port_disp.c

@@ -82,14 +82,9 @@ static lv_display_t *lvgl_port_add_disp_priv(const lvgl_port_display_cfg_t *disp
 static bool lvgl_port_flush_io_ready_callback(esp_lcd_panel_io_handle_t panel_io, esp_lcd_panel_io_event_data_t *edata,
         void *user_ctx);
 #if CONFIG_IDF_TARGET_ESP32S3 && ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 0, 0)
-#if CONFIG_LCD_RGB_ISR_IRAM_SAFE
-static IRAM_ATTR bool lvgl_port_flush_rgb_vsync_ready_callback(esp_lcd_panel_handle_t panel_io,
-        const esp_lcd_rgb_panel_event_data_t *edata, void *user_ctx);
-#else
 static bool lvgl_port_flush_rgb_vsync_ready_callback(esp_lcd_panel_handle_t panel_io,
         const esp_lcd_rgb_panel_event_data_t *edata, void *user_ctx);
 #endif
-#endif
 #if (CONFIG_IDF_TARGET_ESP32P4 && ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 3, 0))
 static bool lvgl_port_flush_dpi_panel_ready_callback(esp_lcd_panel_handle_t panel_io,
         esp_lcd_dpi_panel_event_data_t *edata, void *user_ctx);