Add tri-mode support (SAS/SATA/PCIe).
This includes NVMe device support and adds support for the following adapters:
SAS 3408 SAS 3416 SAS 3508 SAS 3516 SAS 3616 SAS 3708 SAS 3716
Reviewed by: ken, scottl, asomers, mav
Approved by: ken, scottl, mav
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D10095