Port the scmi hwmon driver to the new SCMI sensor interface based on
protocol handles and common devm_get_ops().

Link: https://lore.kernel.org/r/20210316124903.35011-25-cristian.marussi@arm.com
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>