hwmon: Introduce 64-bit energy attribute support

hwmon: Introduce 64-bit energy attribute support

Many chips require 64-bit variables to display the accumulated energy,
even more so since the energy units are micro-Joule. Add new sensor type
"energy64" to support reporting the chip energy as 64-bit values.

Changing the entire hardware monitoring API is not feasible, and it is only
really necessary to support reading 64-bit values for the "energyX_input"
attribute. For this reason, keep the API as-is and use type casts on both
ends to pass 64-bit pointers when reading the accumulated energy. On the
write side (which is only useful for the energyX_enable attribute), keep
passing the written value as long.

Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz> # INA780
Signed-off-by: Guenter Roeck <linux@roeck-us.net>