cyclades: tiocm cleanup

- save one indent level by inverting !fw_loaded condition
- read rs_status on Z and write it after we change all the flags,
  don't do that separately
- remove Y inverted rts/dtr branching, precompute registers and use
  them

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>