Fix (null) problem for AVR32 boards

Currently the U-Boot address ranges for AVR32 boards are
printed like this:
"U-Boot code: (null) -> 0001183c  data: 000188e8 -> 0004e9b0"
This patch fixes this to print:
"U-Boot code: 00000000 -> 0001183c  data: 000188f8 -> 0004e9c0"
Signed-off-by: NReinhard Meyer <info@emk-elektronik.de>

arch/avr32/lib/board.c

@@ -115,8 +115,9 @@ static int init_baudrate(void)
 static int display_banner (void)
 {
 	printf ("\n\n%s\n\n", version_string);
-	printf ("U-Boot code: %p -> %p  data: %p -> %p\n",
-		_text, _etext, _data, _end);
+	printf ("U-Boot code: %08lx -> %08lx  data: %08lx -> %08lx\n",
+		(unsigned long)_text, (unsigned long)_etext,
+		(unsigned long)_data, (unsigned long)_end);
 	return 0;
 }