PCI: brcmstb: Clarify conversion of irq_domain_set_info() param

Just make it clear to the reader that there is a conversion happening, in
this case from an int type to an irq_hw_number_t, an unsigned long int.

Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>

Author: jamesequinlan

drivers/pci/controller/pcie-brcmstb.c

@@ -559,7 +559,7 @@ static int brcm_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 		return hwirq;
 
 	for (i = 0; i < nr_irqs; i++)
-		irq_domain_set_info(domain, virq + i, hwirq + i,
+		irq_domain_set_info(domain, virq + i, (irq_hw_number_t)hwirq + i,
 				    &brcm_msi_bottom_irq_chip, domain->host_data,
 				    handle_edge_irq, NULL, NULL);
 	return 0;