arcmsr(4) update

[John Nemeth <jnemeth%cue.bc.ca@localhost>]

     I've been working on updating the arcmsr(4) driver which
supports Areca RAID controllers.  This driver is originally from
OpenBSD's arc(4) driver but hasn't seen any updates since the
initial import (just maintenance).  I have updated arcmsr(4) to
support all the devices currently support by OpenBSD's arc(4)
driver.  It has been lightly tested on the 1280, 24 port PCIe SATA
controller and somewhat more on an 1880, PCIe 6 Gbps SAS controller.
I have not yet dealt with the bio(4) interface, so that part is
commented out.  Please give it a try, especially with a card that
isn't currently supported.  Also, people good with SMP, please have
a look.  That's not my area, but I did my best to maintain the
locks as it is marked MPSAFE.  I've been testing it with DIAGNOSTIC,
DEBUG, and LOCKDEBUG (this helping to find a locking bug that got
squashed).  BTW, debugging is turned on from boot, so don't expect
to use your console.  :-)  It is located at
http://ftp.NetBSD.org/pub/NetBSD/misc/jnemeth/ .  The two files
there can be dropped into pretty much any recent -current system.