Default to Ultra DMA Mode 6 not 5 when we know we have a native SATA drive.
Default to Ultra DMA Mode 6 not 5 when we know we have a native
SATA drive.

ok grange@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars