hwmon: (lm85) Don't bind to Winbond/Nuvoton WPCD377I

The Winbond/Nuvoton WPCD377I is the reduced version of a Super-I/O
which emulates the National Semiconductor LM96000 hardware monitoring
chips, but without the hardware monitoring part. Instead of plain
disabling the emulation, the vendor left the emulated chip visible,
but all monitored values are always zero. This is rather confusing for
the users. So detect this case and refuse to bind to such fake chips.

This fixes lm-sensors ticket #2182:
http://www.lm-sensors.org/ticket/2182

Signed-off-by: Jean Delvare <khali@linux-fr.org>