PCI: dwc: Define maximum number of vectors

Add a callback to define the maximum number of vectors used by the RC.

Since this is a parameter associated to each SoC IP setting, makes sense
to be configurable and easily visible to future modifications.

Set DesignWare driver vectors number maximum to 256.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Joao Pinto <jpinto@synopsys.com>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
diff --git a/drivers/pci/dwc/pcie-designware-plat.c b/drivers/pci/dwc/pcie-designware-plat.c
index 5416aa8..80a2782 100644
--- a/drivers/pci/dwc/pcie-designware-plat.c
+++ b/drivers/pci/dwc/pcie-designware-plat.c
@@ -38,8 +38,14 @@ static int dw_plat_pcie_host_init(struct pcie_port *pp)
 	return 0;
 }
 
+static void dw_plat_set_num_vectors(struct pcie_port *pp)
+{
+	pp->num_vectors = MAX_MSI_IRQS;
+}
+
 static const struct dw_pcie_host_ops dw_plat_pcie_host_ops = {
 	.host_init = dw_plat_pcie_host_init,
+	.set_num_vectors = dw_plat_set_num_vectors,
 };
 
 static int dw_plat_add_pcie_port(struct pcie_port *pp,