scsi: hisi_sas: Fix type casting and missing static qualifier in debugfs code

Sparse can detect some type casting issues in the debugfs code, so fix it
up.

Also a missing static qualifier is added to hisi_sas_debugfs_to_reg_name().

Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h
index b8b1ded..5bb6759 100644
--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -359,8 +359,8 @@ struct hisi_hba {
 	u32 intr_coal_count;	/* Interrupt count to coalesce */
 
 	/* debugfs memories */
-	void *debugfs_global_reg;
-	void *debugfs_port_reg[HISI_SAS_MAX_PHYS];
+	u32 *debugfs_global_reg;
+	u32 *debugfs_port_reg[HISI_SAS_MAX_PHYS];
 	void *debugfs_complete_hdr[HISI_SAS_MAX_QUEUES];
 	struct hisi_sas_cmd_hdr	*debugfs_cmd_hdr[HISI_SAS_MAX_QUEUES];
 	struct hisi_sas_iost *debugfs_iost;