hw: move private headers to hw/ subdirectories.

Many headers are used only in a single directory.  These can be
kept in hw/.

Signed-off-by: Paolo Bonzini <[email protected]>
diff --git a/hw/pci-bridge/ioh3420.c b/hw/pci-bridge/ioh3420.c
index 5cff61e..bb541eb 100644
--- a/hw/pci-bridge/ioh3420.c
+++ b/hw/pci-bridge/ioh3420.c
@@ -23,7 +23,7 @@
 #include "hw/pci/pci_ids.h"
 #include "hw/pci/msi.h"
 #include "hw/pci/pcie.h"
-#include "hw/ioh3420.h"
+#include "ioh3420.h"
 
 #define PCI_DEVICE_ID_IOH_EPORT         0x3420  /* D0:F0 express mode */
 #define PCI_DEVICE_ID_IOH_REV           0x2