Thank you Areca! 6Gbps 1880 support in illumos

A big thank you goes out to Areca.

Areca have provided the source code for their Solaris driver, including support for the newer 6G RAID adapters. As a result, I've integrated a (somewhat cleaned up) copy this code as an update to arcmsr(7d) in illumos, under generous open source licensing:

changeset:   13305:fb26af81b9b2
tag:         tip
user:        Garrett D'Amore 
date:        Fri Mar 25 22:14:56 2011 -0700
description:
      834 need support for Areca 1880 6Gbps
      Reviewed by: Dan McDonald <danmcd@nexenta.com>
      Reviewed by: Albert Lee <trisk@nexenta.com>
      Reviewed by: Richard Lowe <richlowe@richlowe.net>

This will make another HBA option available to folks. (Note these cards do support a JBOD mode, so you don't have to use hardware RAID -- indeed I would recommend that you don't when you have ZFS on the disks.