blackfin: Subtract ANOMALY_05000230 on quot

Fix bug - up arrow key works abnormal for bf561 ezkit board
Signed-off-by: NGraf Yang <graf.yang@analog.com>
Signed-off-by: NBryan Wu <cooloney@kernel.org>
Signed-off-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/serial/bfin_5xx.c

@@ -760,7 +760,7 @@ bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
 	}
 
 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
-	quot = uart_get_divisor(port, baud);
+	quot = uart_get_divisor(port, baud) - ANOMALY_05000230;
 	spin_lock_irqsave(&uart->port.lock, flags);
 
 	UART_SET_ANOMALY_THRESHOLD(uart, USEC_PER_SEC / baud * 15);