virtio: Move virtio-pci to hw library

This module has no target dependencies (except for target_phys_addr_t
size) and can thus be built as part of libhw.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Makefile.objs

@@ -170,6 +170,7 @@ user-obj-y += cutils.o cache-utils.o
 hw-obj-y =
 hw-obj-y += vl.o loader.o
 hw-obj-$(CONFIG_VIRTIO) += virtio.o virtio-console.o
+hw-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
 hw-obj-y += fw_cfg.o
 hw-obj-$(CONFIG_PCI) += pci.o pci_bridge.o
 hw-obj-$(CONFIG_PCI) += msix.o msi.o

Makefile.target

@@ -190,7 +190,6 @@ obj-y = arch_init.o cpus.o monitor.o machine.o gdbstub.o balloon.o
 # need to fix this properly
 obj-$(CONFIG_NO_PCI) += pci-stub.o
 obj-$(CONFIG_VIRTIO) += virtio-blk.o virtio-balloon.o virtio-net.o virtio-serial-bus.o
-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
 obj-y += vhost_net.o
 obj-$(CONFIG_VHOST_NET) += vhost.o
 obj-$(CONFIG_REALLY_VIRTFS) += 9pfs/virtio-9p.o