tty: i386: rs232 fix
tty: i386: rs232 fix

	. ignore interrupt (stop interrupt check loop) if
	  interrupt bit not set; limit loop too
	. mask off other bits when testing bits in the status register
	. this fixes rs232 output that would otherwise never get re-triggered
	  as too many bits were set in the status byte to match the
	  possibilities.

Change-Id: I311c93377fa8fb477ee9a756455fdeda780e6ba1

veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi,veritas-shine/minix3-rpi