[SCSI] isci: oem parameter format v1.3 (cable select)

v1.3 allows the attenuation of the attached cables to be specified to
the driver in terms of 'short', 'medium', and 'long' (see probe_roms.h).
These settings (per phy) are retrieved from the platform oem-parameters
(BIOS rom) or via a module parameter override.

Reviewed-by: Jiangbi Liu <jiangbi.liu@intel.com>
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/isci/isci.h b/drivers/scsi/isci/isci.h
index 8efeb6b..234ab46 100644
--- a/drivers/scsi/isci/isci.h
+++ b/drivers/scsi/isci/isci.h
@@ -480,6 +480,7 @@
 extern u16 stp_inactive_to;
 extern unsigned char phy_gen;
 extern unsigned char max_concurr_spinup;
+extern uint cable_selection_override;
 
 irqreturn_t isci_msix_isr(int vec, void *data);
 irqreturn_t isci_intx_isr(int vec, void *data);