Update FileX driver's state after UNINIT

In filex nor flash driver, `current_driver->initialized` is set to `FX_TRUE` after FX_DRIVER_INIT, but this state is not set to `FX_FALSE` in FX_DRIVER_UNINIT, here is the code:

https://github.com/STMicroelectronics/x-cube-azrtos-h7/blob/437ec3bb3455a26c535de52f0fc7f553c739acb7/Middlewares/ST/filex/common/drivers/fx_stm32_levelx_nor_driver.c#L135C1-L139C1

Is it a bug or by design?