docs/specs/pci-ids: Fix markup

This fixes the markup of the PCI and PCIe Expander Bridge entries to be
consistent with the rest of the file.

Signed-off-by: George Matsumura <gorg@gorgnet.net>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240805031012.16547-4-gorg@gorgnet.net>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

docs/specs/pci-ids.rst

@@ -77,11 +77,11 @@ PCI devices (other than virtio):
 1b36:0008
   PCIe host bridge
 1b36:0009
-  PCI Expander Bridge (-device pxb)
+  PCI Expander Bridge (``-device pxb``)
 1b36:000a
   PCI-PCI bridge (multiseat)
 1b36:000b
-  PCIe Expander Bridge (-device pxb-pcie)
+  PCIe Expander Bridge (``-device pxb-pcie``)
 1b36:000c
   PCIe Root Port (``-device pcie-root-port``)
 1b36:000d