pci-ids.rst: add Red Hat pci-id for RISC-V IOMMU device

The RISC-V IOMMU PCI device we're going to add next is a reference
implementation of the riscv-iommu spec [1], which predicts that the
IOMMU can be implemented as a PCIe device.

However, RISC-V International (RVI), the entity that ratified the
riscv-iommu spec, didn't bother assigning a PCI ID for this IOMMU PCIe
implementation that the spec predicts. This puts us in an uncommon
situation because we want to add the reference IOMMU PCIe implementation
but we don't have a PCI ID for it.

Given that RVI doesn't provide a PCI ID for it we reached out to Red Hat
and Gerd Hoffman, and they were kind enough to give us a PCI ID for the
RISC-V IOMMU PCI reference device.

Thanks Red Hat and Gerd for this RISC-V IOMMU PCIe device ID.

[1] https://github.com/riscv-non-isa/riscv-iommu/releases/tag/v1.0.0

Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Message-ID: <20241016204038.649340-5-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

docs/specs/pci-ids.rst

@@ -98,6 +98,8 @@ PCI devices (other than virtio):
   PCI ACPI ERST device (``-device acpi-erst``)
 1b36:0013
   PCI UFS device (``-device ufs``)
+1b36:0014
+  PCI RISC-V IOMMU device
 
 All these devices are documented in :doc:`index`.