Stefan Dietrich reports invalid temperature source messages on Asus Formula
XII Z490.

nct6775 nct6775.656: Invalid temperature source 28 at index 0,
		source register 0x100, temp register 0x73

Debugging suggests that temperature source 28 reports the CPU temperature.
Let's assume that temperature sources 28 and 29 reflect "PECI Agent {0,1}
Calibration", similar to other chips of the series.
Reported-by: Stefan Dietrich <roots@gmx.de>
Cc: Stefan Dietrich <roots@gmx.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>