CVE-2023-53094 tty: serial: fsl_lpuart: fix race on RX DMA shutdown

In the Linux kernel, the following vulnerability has been resolved: tty: serial: fsllpuart: fix race on RX DMA shutdown From time to time DMA completion can come in the middle of DMA shutdown: : : lpuart32shutdown lpuartdmashutdown deltimersync lpuartdmarxcomplete lpuartcopyrxtotty modtimer...