PCI/migration merge vmstate_pci_device and vmstate_pcie_device

PCI/migration merge vmstate_pci_device and vmstate_pcie_device

The vmstate_pci_device and vmstate_pcie_devices differ
just in the size of one buffer; combine the two using a _TEST
macro.

I think this is safe as long as everywhere which currently
uses either of these two uses the right type.

One thing that concerns me is that some places use pci_device_load/save
which does some irq mangling, but others just use the VMSTATE_PCI_DEVICE
macro - how are they getting the same irq mangling?

This passes a smoke test migrate of:
./x86_64-softmmu/qemu-system-x86_64 -M pc,accel=kvm -m 1024
./littlefed20.img -device e1000e -device virtio-net -device
e1000 -device virtio-rng -device megasas -device megasas-gen2 -device
ioh3420 -device nec-usb-xhci

to an unmodified qemu.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20161214195829.18241-1-dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>