dt-bindings: hwmon: (mr75203) add coefficient properties for the thermal equation

Add optional temperature coefficient properties:
 *) moortec,ts-coeff-g
 *) moortec,ts-coeff-h
 *) moortec,ts-coeff-cal5
 *) moortec,ts-coeff-j
If defined they shall be used instead of defaults.

The coefficients were added to device tree on top of the series property
(which can be used to select between series 5 and series 6), because
coefficients can vary between product and product, and code defaults might
not be accurate enough.

Signed-off-by: Eliav Farber <farbere@amazon.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220908152449.35457-19-farbere@amazon.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>