drivers: serial: xlnx_xuartps: Fix interrupt-driven operation

Fixes interrupt-driven operation. With the previous way of
handling the TX FIFO and the interrupt flags, the operation
of the UART was prone to stalling when using it as the
console I/O device.

Signed-off-by: Immo Birnbaum <Immo.Birnbaum@weidmueller.com>
1 file changed