pci_host_generic: allocate PCI, not CPU addresses.

[crowston_protonmail.com]

Summary

Resolve a bug on systems where the PCI controller's view of the address space of the system memory is not consistent with the CPU's. We now assume all addresses passed to pci_host_generic_core_alloc_resource() are PCI addresses, and
store them as such. Only in generic_pcie_activate_resource() is the PCI address is translated to a CPU address.

Test Plan

Tested on my Rpi4 with PCI-E controller driver.

[andrew]

Sorry, I missed this. I fixed it in a different way in rS362493 by extracting the translation code into a new function.

I've tested it on qemu-system-arm -machine virt as this also has PCI address != phys address.