hwmon: (lm90) Support ADT7461 in extended mode

Support ADT7461 in extended temperature range mode, which will change
the range of readings from 0..127 to -64..191 degC.  Adjust the
register conversion functions accordingly.

Signed-off-by: Nate Case <ncase@xes-inc.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Martyn Welch <martyn.welch@gefanuc.com>
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index ebacc0a..96701e0 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -510,11 +510,8 @@
 	depends on I2C
 	help
 	  If you say yes here you get support for National Semiconductor LM90,
-	  LM86, LM89 and LM99, Analog Devices ADM1032 and Maxim MAX6657,
-	  MAX6658, MAX6659, MAX6680 and MAX6681 sensor chips.
-
-	  The Analog Devices ADT7461 sensor chip is also supported, but only
-	  if found in ADM1032 compatibility mode.
+	  LM86, LM89 and LM99, Analog Devices ADM1032 and ADT7461, and Maxim
+	  MAX6657, MAX6658, MAX6659, MAX6680 and MAX6681 sensor chips.
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called lm90.