serial: txx9: remove duplicate TXX9_SIFCR_TDIL_MASK define

The TXX9_SIFCR_TDIL_MASK define is cut and pasted twice so we can delete
the second instance.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/serial_txx9.c

@@ -142,7 +142,6 @@ struct uart_txx9_port {
 #define TXX9_SIFCR_RDIL_12	0x00000180
 #define TXX9_SIFCR_RDIL_MAX	0x00000180
 #define TXX9_SIFCR_TDIL_MASK	0x00000018
-#define TXX9_SIFCR_TDIL_MASK	0x00000018
 #define TXX9_SIFCR_TDIL_1	0x00000000
 #define TXX9_SIFCR_TDIL_4	0x00000001
 #define TXX9_SIFCR_TDIL_8	0x00000010