[SCSI] isci: export phy events via ->lldd_control_phy()

Allow the sas-transport-class to update events for local phys via a new
PHY_FUNC_GET_EVENTS command to ->lldd_control_phy().  Fixup drivers that
are not prepared for new enum phy_func values, and unify
->lldd_control_phy() error codes.

These are the SAS defined phy events that are reported in a
smp-report-phy-error-log command:
 * /sys/class/sas_phy/<phyX>/invalid_dword_count
 * /sys/class/sas_phy/<phyX>/running_disparity_error_count
 * /sys/class/sas_phy/<phyX>/loss_of_dword_sync_count
 * /sys/class/sas_phy/<phyX>/phy_reset_problem_count

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/include/scsi/sas.h b/include/scsi/sas.h
index cfdbe95..3673d68 100644
--- a/include/scsi/sas.h
+++ b/include/scsi/sas.h
@@ -122,6 +122,7 @@
 	PHY_FUNC_TX_SATA_PS_SIGNAL,
 	PHY_FUNC_RELEASE_SPINUP_HOLD = 0x10, /* LOCAL PORT ONLY! */
 	PHY_FUNC_SET_LINK_RATE,
+	PHY_FUNC_GET_EVENTS,
 };
 
 /* SAS LLDD would need to report only _very_few_ of those, like BROADCAST.