PCI: loongson: Work around LS7A incorrect Interrupt Pin registers

PCI: loongson: Work around LS7A incorrect Interrupt Pin registers

Several devices integrated into LS7A report 1 (which means they use
INTA) in their Interrupt Pin registers, but they actually use a different
interrupt.

Add a quirk to override the incorrect Interrupt Pin values.

This is only needed by ACPI-based systems. For DT-based systems,
pci_assign_irq() ignores the Interrupt Pin register except to learn that
the device uses INTx and the host bridge .map_irq() function
(loongson_map_irq()) learns the IRQ mapping via DT and of_irq_parse_pci().

[bhelgaas: drop PCIE_PORT_x, OHCI, GPU since they are function 0 and don't
need the quirk, squash in updates from
https://lore.kernel.org/r/CAAhV-H40_o+9KS1t67O98GusM38pDaiB4bssxd3KQZpAByfnLg@mail.gmail.com]
Link: https://lore.kernel.org/r/20220714124216.1489304-8-chenhuacai@loongson.cn
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>