ASoC: pcm512x: Fix divide by zero issue

commit f073faa7 upstream.

If den=1 and pllin_rate>20MHz then den and num are adjusted to 0
causing a divide by zero error a few lines further on. Therefore
this patch correctly scales num and den such that
pllin_rate/den < 20MHz as required in the device data sheet.
Signed-off-by: Howard Mitchell <hm@hmbedded.co.uk>
Signed-off-by: Mark Brown <broonie@sirena.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

sound/soc/codecs/pcm512x.c

@@ -576,8 +576,8 @@ static int pcm512x_find_pll_coeff(struct snd_soc_dai *dai,
 
 	/* pllin_rate / P (or here, den) cannot be greater than 20 MHz */
 	if (pllin_rate / den > 20000000 && num < 8) {
-		num *= 20000000 / (pllin_rate / den);
-		den *= 20000000 / (pllin_rate / den);
+		num *= DIV_ROUND_UP(pllin_rate / den, 20000000);
+		den *= DIV_ROUND_UP(pllin_rate / den, 20000000);
 	}
 	dev_dbg(dev, "num / den = %lu / %lu\n", num, den);