Intel drives have an optimal alignment for I/O. While they honor I/Os
that cross this boundary, they perform better when this isn't the
case. Intel uses the 3rd byte in the vendor specific area for
this. The DC P3500 was previously listed without any explanation. Add
the DC P3520 and DC P4500 to the list.

There won't be any others drives needing this quirk. Intel has
standardized a field in the namespace data in 1.3 (noiob). A future
patch will use that if it exists, with fallback to this method.

Submitted by: Keith Busch
Reviewed by: jimharris@