Revert "iommu/amd: Prevent binding other PCI drivers to IOMMU PCI devices"

Commit 991de2e ("PCI, x86: Implement pcibios_alloc_irq() and
pcibios_free_irq()") changed IRQ handling on PCI driver probing.
It inadvertently broke resume from system sleep on AMD platforms:

  https://lore.kernel.org/r/[email protected]/

This was fixed by two independent commits:

* 8affb48 ("x86/PCI: Don't alloc pcibios-irq when MSI is enabled")
* cbbc00b ("iommu/amd: Prevent binding other PCI drivers to IOMMU PCI devices")

The breaking change and one of these two fixes were subsequently reverted:

* fe25d07 ("Revert "x86/PCI: Don't alloc pcibios-irq when MSI is enabled"")
* 6c777e8 ("Revert "PCI, x86: Implement pcibios_alloc_irq() and pcibios_free_irq()"")

This rendered the second fix unnecessary, so revert it as well.  It used
the match_driver flag in struct pci_dev, which is internal to the PCI core
and not supposed to be touched by arbitrary drivers.

Signed-off-by: Lukas Wunner <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Signed-off-by: Krzysztof Wilczyński <[email protected]>
Acked-by: Joerg Roedel <[email protected]>
Link: https://patch.msgid.link/9a3ddff5cc49512044f963ba0904347bd404094d.1745572340.git.lukas@wunner.de

Author: l1k

drivers/iommu/amd/init.c

@@ -2030,9 +2030,6 @@ static int __init iommu_init_pci(struct amd_iommu *iommu)
 	if (!iommu->dev)
 		return -ENODEV;
 
-	/* Prevent binding other PCI device drivers to IOMMU devices */
-	iommu->dev->match_driver = false;
-
 	/* ACPI _PRT won't have an IRQ for IOMMU */
 	iommu->dev->irq_managed = 1;