tty: simserial: drop unused iflag macro

Drop the RELEVANT_IFLAG() macro which hasn't been used for over a
decade.

Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/ia64/hp/sim/simserial.c

@@ -324,8 +324,6 @@ static int rs_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
 	return -ENOIOCTLCMD;
 }
 
-#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
-
 /*
  * This routine will shutdown a serial port; interrupts are disabled, and
  * DTR is dropped if the hangup on close termio flag is on.