[SCSI] isci: Adding documentation to API change and fixup sysfs registration

Adding API update for adding isci_id entry scsi_host sysfs entry.
Also fixing up the sysfs registration to the scsi_host template

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/Documentation/ABI/testing/sysfs-class-scsi_host b/Documentation/ABI/testing/sysfs-class-scsi_host
new file mode 100644
index 0000000..29a4f89
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-scsi_host
@@ -0,0 +1,13 @@
+What:		/sys/class/scsi_host/hostX/isci_id
+Date:		June 2011
+Contact:	Dave Jiang <dave.jiang@intel.com>
+Description:
+		This file contains the enumerated host ID for the Intel
+		SCU controller. The Intel(R) C600 Series Chipset SATA/SAS
+		Storage Control Unit embeds up to two 4-port controllers in
+		a single PCI device.  The controllers are enumerated in order
+		which usually means the lowest number scsi_host corresponds
+		with the first controller, but this association is not
+		guaranteed.  The 'isci_id' attribute unambiguously identifies
+		the controller index: '0' for the first controller,
+		'1' for the second.