MOS7720 has no tiocmget method

Fix the tiocmget/mset handling on the mos7720 USB serial port.

[Minor space reformatting for coding style - Alan]

Signed-off-by: Kees Schoenmakers <k.schoenmakers@sigmae.nl>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>