Drop legacy ISA address support from the it87 driver. All supported
chips are Super-I/O chips, so the device ISA address can be safely read
from Super-I/O space rather than blindly assumed.

Two nearby inaccurate documentation statements have been fixed as well:
* The IT8705F doesn't have an SMBus interface.
* The SiS950 doesn't have a distinct prefix.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>