hwmon: (lm87) Add support for configuration through platform_data

The lm87 driver normally assumes that firmware configured the chip
correctly.  Since this is not always the case, alllow platform code to
set the channel register value via platform_data.  All other
configuration registers can be changed after driver initialisation.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/Documentation/hwmon/lm87 b/Documentation/hwmon/lm87
index ec27aa1..6b47b67 100644
--- a/Documentation/hwmon/lm87
+++ b/Documentation/hwmon/lm87
@@ -65,11 +65,10 @@
 depending on the hardware configuration.
 
 Some functions share pins, so not all functions are available at the same
-time. Which are depends on the hardware setup. This driver assumes that
-the BIOS configured the chip correctly. In that respect, it differs from
-the original driver (from lm_sensors for Linux 2.4), which would force the
-LM87 to an arbitrary, compile-time chosen mode, regardless of the actual
-chipset wiring.
+time. Which are depends on the hardware setup. This driver normally
+assumes that firmware configured the chip correctly. Where this is not
+the case, platform code must set the I2C client's platform_data to point
+to a u8 value to be written to the channel register.
 
 For reference, here is the list of exclusive functions:
  - in0+in5 (default) or temp3