USB: serial: cp210x: use tcflag_t to fix incompatible pointer type

On sparc32, tcflag_t is unsigned long, unlike all other architectures:

    drivers/usb/serial/cp210x.c: In function 'cp210x_get_termios':
    drivers/usb/serial/cp210x.c:717:3: warning: passing argument 2 of 'cp210x_get_termios_port' from incompatible pointer type
       cp210x_get_termios_port(tty->driver_data,
       ^
    drivers/usb/serial/cp210x.c:35:13: note: expected 'unsigned int *' but argument is of type 'tcflag_t *'
     static void cp210x_get_termios_port(struct usb_serial_port *port,
		 ^

Consistently use tcflag_t to fix this.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Johan Hovold <johan@kernel.org>