Just disable RAID mode. It'll be picked up as if it were IDE.
On my DS3 RAID mode is not selected by default, standard IDE mode is. If the OP's SATA drive doesn't work right off the bat I might try switching to SATA legacy mode in the bios as SATA native is selected by default. ...but I'd not think you'd need to do this or anything else special to get a single SATA drive to work. ...on this board SATA2 is nothing special that should require anything special. I have 3 SATA 2 drives installed and never had to pay attention to any special bios settings to get them to work.
I've used bios versions F7-F9 with good results. Good luck.