Update ciss(4) man page. We absolutely support performant mode of operation

on this controller.  Indicate that the 5300 is the *only* controller that
will only work in simple mode.

Bus rescans should not be needed now and I consider it a bug if disks do
not appear or dissapear when created or destroyed.

Obtained from:	Yahoo! Inc

share/man/man4/ciss.4

@@ -62,14 +62,11 @@ control protocol from earlier Compaq adapter families.
 .Pp
 Currently
 .Nm
-only supports the
+supports the
 .Dq simple
-transport layer over PCI.
-This interface (ab)uses the I2O register set (specifically the post
-queues) to exchange commands with the adapter.
-Other interfaces are available, but we are not supposed to know about them,
-and it is dubious whether they would provide major performance improvements
-except under extreme load.
+and
+.Dq performant
+transport layer.
 .Pp
 Non-disk devices (such as internal DATs and devices
 attached to the external SCSI bus) are supported as normal CAM devices
@@ -82,8 +79,8 @@ Direct Access devices (such as disk
 drives) are only exposed as
 .Xr pass 4
 devices.
-Hot-insertion and removal of devices is supported but a bus
-rescan might be necessary.
+Hot-insertion and removal of devices is supported and notification messages
+will be reported to the console and logs.  
 .Pp
 The problem which adapter freezes with the message
 .Dq ADAPTER HEARTBEAT FAILED
@@ -97,7 +94,7 @@ driver include:
 .Pp
 .Bl -bullet -compact
 .It
-Compaq Smart Array 5300
+Compaq Smart Array 5300 (simple mode only)
 .It
 Compaq Smart Array 532
 .It