ASoC: tegra: Fix build error due to 64-by-32 division

Build errors are seen on 32-bit platforms because of a plain 64-by-32
division. For example, following build erros were reported.

"ERROR: modpost: "__udivdi3" [sound/soc/tegra/snd-soc-tegra210-dmic.ko]
 undefined!"
"ERROR: modpost: "__divdi3" [sound/soc/tegra/snd-soc-tegra210-dmic.ko]
 undefined!"

This can be fixed by using div_u64() helper from 'math64.h' header.

Fixes: 8c8ff982 ("ASoC: tegra: Add Tegra210 based DMIC driver")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Link: https://lore.kernel.org/r/1595492011-2411-1-git-send-email-spujar@nvidia.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/tegra/tegra210_dmic.c

@@ -6,6 +6,7 @@
 
 #include <linux/clk.h>
 #include <linux/device.h>
+#include <linux/math64.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
@@ -129,7 +130,7 @@ static int tegra210_dmic_hw_params(struct snd_pcm_substream *substream,
 	 * Boost Gain Volume control has 100x factor.
 	 */
 	if (dmic->boost_gain)
-		gain_q23 = (gain_q23 * dmic->boost_gain) / 100;
+		gain_q23 = div_u64(gain_q23 * dmic->boost_gain, 100);
 
 	regmap_write(dmic->regmap, TEGRA210_DMIC_LP_FILTER_GAIN,
 		     (unsigned int)gain_q23);