serial: 8250_fintek: Fix finding base_port with activated SuperIO

The SuperIO will be configured at boot time by BIOS, but some BIOS
will not deactivate the SuperIO when the end of configuration. It'll
lead to mismatch for pdata->base_port in probe_setup_port(). So we'll
deactivate all SuperIO before activate special base_port in
fintek_8250_enter_key().

Tested on iBASE MI802.

Cc: stable@vger.kernel.org
Tested-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Reviewd-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_fintek.c

@@ -128,6 +128,9 @@ static int fintek_8250_enter_key(u16 base_port, u8 key)
 	if (!request_muxed_region(base_port, 2, "8250_fintek"))
 		return -EBUSY;
 
+	/* Force to deactive all SuperIO in this base_port */
+	outb(EXIT_KEY, base_port + ADDR_PORT);
+
 	outb(key, base_port + ADDR_PORT);
 	outb(key, base_port + ADDR_PORT);
 	return 0;