util/superiotool: Register fix for Fintek F71869AD

Fixed F71869AD based on the proper datasheet:
http://www.alldatasheet.com/datasheet-pdf/pdf/459074/FINTEK/F71869AD.html

Change-Id: If22341551c6a1a9bbae088801a6194f7b5b6bf4d
Signed-off-by: Wilbert Duijvenvoorde <w.a.n.duijvenvoorde@gmail.com>
Reviewed-on: http://review.coreboot.org/5405
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Rudolf Marek <r.marek@assembler.cz>