hwmon: (sfctemp) Add StarFive JH71x0 temperature sensor

Add driver for the StarFive JH71x0 temperature sensor. You
can enable/disable it and read temperature in milli Celcius
through sysfs.

Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Co-developed-by: Samin Guo <samin.guo@starfivetech.com>
Signed-off-by: Samin Guo <samin.guo@starfivetech.com>
Signed-off-by: Hal Feng <hal.feng@starfivetech.com>
Link: https://lore.kernel.org/r/20230321022644.107027-3-hal.feng@starfivetech.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>