PCI: dwc: Constify dw_pcie_host_ops structures

The dw_pcie_host_ops structures are never modified.  Constify these
structures such that these can be write-protected.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index c6a8405..b4d2a89 100644
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -162,7 +162,7 @@ struct pcie_port {
 	struct resource		*mem;
 	struct resource		*busn;
 	int			irq;
-	struct dw_pcie_host_ops	*ops;
+	const struct dw_pcie_host_ops *ops;
 	int			msi_irq;
 	struct irq_domain	*irq_domain;
 	unsigned long		msi_data;