iommu/vt-d: Remove domain search for PCI/MSI[X]

Now that the domain can be retrieved through device::msi_domain the domain
search for PCI_MSI[X] is not longer required. Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20200826112334.305699301@linutronix.de

Author: KAGA-KOKO

drivers/iommu/intel/irq_remapping.c

@@ -1138,9 +1138,6 @@ static struct irq_domain *intel_get_irq_domain(struct irq_alloc_info *info)
 		return map_ioapic_to_ir(info->devid);
 	case X86_IRQ_ALLOC_TYPE_HPET_GET_PARENT:
 		return map_hpet_to_ir(info->devid);
-	case X86_IRQ_ALLOC_TYPE_PCI_MSI:
-	case X86_IRQ_ALLOC_TYPE_PCI_MSIX:
-		return map_dev_to_ir(msi_desc_to_pci_dev(info->desc));
 	default:
 		WARN_ON_ONCE(1);
 		return NULL;