Super-IO accesses may fail on a system with no or unmapped LPC bus.

Also, other drivers may attempt to access the LPC bus at the same time,
resulting in undefined behavior.

Use request_muxed_region() to ensure that IO access on the requested
address space is supported, and to ensure that access by multiple drivers
is synchronized.

Fixes: 2219cd81 ("hwmon/vt1211: Add probing of alternate config index port")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>