PowerPC: Squash warning in mpc512x serial.c

serial.c: In function 'serial_setbrg_dev':
serial.c:143: warning: format '%d' expects type 'int', but argument 4 has type
'long unsigned int'

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Mike Frysinger <vapier@gentoo.org>

arch/powerpc/cpu/mpc512x/serial.c

@@ -140,7 +140,7 @@ void serial_setbrg_dev(unsigned int idx)
 		if (br_env)
 			baudrate = simple_strtoul(br_env, NULL, 10);
 
-		debug("%s: idx %d, baudrate %d\n", __func__, idx, baudrate);
+		debug("%s: idx %d, baudrate %ld\n", __func__, idx, baudrate);
 	}
 
 	/* calculate divisor for setting PSC CTUR and CTLR registers */