Linux 32bit BAR atomic repositioning

Description:

Linux will attempt to reposition 32bit BARs without disabling memory decoding: https://elixir.bootlin.com/linux/v6.13.2/source/drivers/pci/setup-res.c#L92

This won't work with the current vPCI code on a PVH dom0, as the current vPCI logic in Xen requires that memory decoding is disabled to change the position of BARs.

Supporting such (according to the spec) valid use-case will require changes to vPCI to remap BARs while memory decoding is enabled.