Header rearrangement.

I want to get to the point where any header in include/ reflects a
standard user-level header (e.g. a POSIX header), while everything that's
specific to gPXE lives in include/gpxe/.  Headers that reflect a Linux
header (e.g. if_ether.h) should also be in include/gpxe/, with the same
name as the Linux header and, preferably, the same names used for the
definitions.

src/arch/i386/core/pci_io.c

@@ -12,7 +12,7 @@
 */
 #include "etherboot.h"
 #include "init.h"
-#include "pci.h"
+#include <gpxe/pci.h>
 #include "pci_io.h"
 #ifdef KEEP_IT_REAL
 #include "realmode.h"

src/arch/i386/drivers/net/undi.c

@@ -33,7 +33,7 @@ $Id$
 /* to get the interface to the body of the program */
 #include "nic.h"
 /* to get the PCI support functions, if this is a PCI NIC */
-#include "pci.h"
+#include <gpxe/pci.h>
 /* UNDI and PXE defines.  Includes pxe.h. */
 #include "undi.h"
 /* 8259 PIC defines */

src/arch/i386/include/relocate.h

@@ -4,7 +4,7 @@
 /* relocate() is conceptually impossible with KEEP_IT_REAL */
 #ifndef KEEP_IT_REAL
 
-#include "tables.h"
+#include <gpxe/tables.h>
 
 /* An entry in the post-relocation function table */
 struct post_reloc_fn {

src/arch/i386/prefix/select_pci.c

@@ -1,5 +1,5 @@
 #include "dev.h"
-#include "pci.h"
+#include <gpxe/pci.h>
 #include "registers.h"
 
 /*