samples: drivers: video: capture_to_lvgl: Adjust Kconfig symbols

Adjust the Kconfig symbols of the capture to lvgl sample. LV_MEM_CUSTOM has
been removed in v9.0 and LV_USE_IMG has been changed to LV_USE_IMAGE.

Signed-off-by: Fabian Blatz <fabianblatz@gmail.com>

samples/drivers/video/capture_to_lvgl/prj.conf

@@ -11,7 +11,6 @@ CONFIG_DISPLAY_LOG_LEVEL_ERR=y
 
 CONFIG_LVGL=y
 CONFIG_LV_CONF_MINIMAL=y
-CONFIG_LV_MEM_CUSTOM=y
-CONFIG_LV_USE_IMG=y
+CONFIG_LV_USE_IMAGE=y
 CONFIG_LV_Z_MEM_POOL_SIZE=16384
 CONFIG_LV_USE_PERF_MONITOR=y