hw/pci-assign: split pci-assign.c

We will try to reuse assign_dev_load_option_rom in xen side, and
especially its a good beginning to unify pci assign codes both on
kvm and xen in the future.

[Fix build for Windows]

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>

include/hw/pci/pci-assign.h

@@ -0,0 +1,27 @@
+/*
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ * Just split from hw/i386/kvm/pci-assign.c.
+ */
+#ifndef PCI_ASSIGN_H
+#define PCI_ASSIGN_H
+
+#include "hw/pci/pci.h"
+
+//#define DEVICE_ASSIGNMENT_DEBUG
+
+#ifdef DEVICE_ASSIGNMENT_DEBUG
+#define DEBUG(fmt, ...)                                       \
+    do {                                                      \
+        fprintf(stderr, "%s: " fmt, __func__ , __VA_ARGS__);  \
+    } while (0)
+#else
+#define DEBUG(fmt, ...)
+#endif
+
+void *pci_assign_dev_load_option_rom(PCIDevice *dev, struct Object *owner,
+                                     int *size, unsigned int domain,
+                                     unsigned int bus, unsigned int slot,
+                                     unsigned int function);
+#endif /* PCI_ASSIGN_H */