Updated PXE UDP implementation to use the new Etherboot UDP API.

Updated PXE API dispatcher to use copy_{to,from}_user, and moved to
arch/i386 since the implementation is quite architecture-dependent.
(The individual PXE API calls can be largely
architecture-independent.)

src/interface/pxe/pxe_undi.c

@@ -22,6 +22,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#if 0
+
 #include "pxe.h"
 
 typedef struct {
@@ -536,3 +538,5 @@ PXENV_EXIT_t pxenv_undi_isr ( struct s_PXENV_UNDI_ISR *undi_isr ) {
 	undi_isr->Status = PXENV_STATUS_SUCCESS;
 	return PXENV_EXIT_SUCCESS;
 }
+
+#endif