ppc4xx: Move cpu/ppc4xx/vecnum.h into include path

This patch allows the use of 4xx interrupt vector number defines
in board specific code outside cpu/ppc4xx.

Signed-off-by: Matthias Fuchs <matthias.fuchs@esd-electronics.com>
diff --git a/cpu/ppc4xx/iop480_uart.c b/cpu/ppc4xx/iop480_uart.c
index 8dd2267..3af0767 100644
--- a/cpu/ppc4xx/iop480_uart.c
+++ b/cpu/ppc4xx/iop480_uart.c
@@ -26,7 +26,7 @@
 #include <asm/processor.h>
 #include <asm/io.h>
 #include <watchdog.h>
-#include "vecnum.h"
+#include <asm/ppc4xx-intvec.h>
 
 #ifdef CONFIG_SERIAL_MULTI
 #include <serial.h>