hwmon: (it87) Add support for the ITE IT8603E

Add support for IT8603E.

This closes bug #57861:
https://bugzilla.kernel.org/show_bug.cgi?id=57861



[JD: Fixes and clean-ups.]

Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>