hwmon: (lm90) Add max6654 support to lm90 driver

Add support for the Maxim MAX6654 to the lm90 driver.

The MAX6654 is a temperature sensor, similar to the others,
but with some differences regarding the configuration
register, and the sampling rate at which extended resolution
becomes possible.

Signed-off-by: Josh Lehan <krellan@google.com>
Link: https://lore.kernel.org/r/20200513184248.145765-1-krellan@google.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/lm90.rst

@@ -123,6 +123,18 @@ Supported chips:
 
 	       http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3497
 
+  * Maxim MAX6654
+
+    Prefix: 'max6654'
+
+    Addresses scanned: I2C 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
+
+			   0x4c, 0x4d and 0x4e
+
+    Datasheet: Publicly available at the Maxim website
+
+	       https://www.maximintegrated.com/en/products/sensors/MAX6654.html
+
   * Maxim MAX6657
 
     Prefix: 'max6657'
@@ -301,6 +313,13 @@ ADT7461, ADT7461A, NCT1008:
   * Extended temperature range (breaks compatibility)
   * Lower resolution for remote temperature
 
+MAX6654:
+  * Better local resolution
+  * Selectable address
+  * Remote sensor type selection
+  * Extended temperature range
+  * Extended resolution only available when conversion rate <= 1 Hz
+
 MAX6657 and MAX6658:
   * Better local resolution
   * Remote sensor type selection
@@ -336,8 +355,8 @@ SA56004X:
 
 All temperature values are given in degrees Celsius. Resolution
 is 1.0 degree for the local temperature, 0.125 degree for the remote
-temperature, except for the MAX6657, MAX6658 and MAX6659 which have a
-resolution of 0.125 degree for both temperatures.
+temperature, except for the MAX6654, MAX6657, MAX6658 and MAX6659 which have
+a resolution of 0.125 degree for both temperatures.
 
 Each sensor has its own high and low limits, plus a critical limit.
 Additionally, there is a relative hysteresis value common to both critical