tty: xilinx_uartps: Initialise the read_status_mask

Initialise the read status in probe.
It will be checked in the isr so to have the default values lets initialise
in probe.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/20220729114748.18332-4-shubhrajyoti.datta@xilinx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/xilinx_uartps.c

@@ -1559,6 +1559,8 @@ static int cdns_uart_probe(struct platform_device *pdev)
 	port->dev = &pdev->dev;
 	port->uartclk = clk_get_rate(cdns_uart_data->uartclk);
 	port->private_data = cdns_uart_data;
+	port->read_status_mask = CDNS_UART_IXR_TXEMPTY | CDNS_UART_IXR_RXTRIG |
+			CDNS_UART_IXR_OVERRUN | CDNS_UART_IXR_TOUT;
 	cdns_uart_data->port = port;
 	platform_set_drvdata(pdev, port);