USB: digi_acceleport: fix termios and also readability a bit

- Expand some x&y to x & y so I could read it when checking
- Clear CMSPAR bit in the termios (as the driver does not support it)
- Encode the speed using the new tty_encode_baud_rate facility

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>