ASoC: stm32: dfsdm: fix typo in comment

Spelling mistake (triple letters) in comment.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Link: https://lore.kernel.org/r/20220521111145.81697-76-Julia.Lawall@inria.fr
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/stm/stm32_adfsdm.c

@@ -296,7 +296,7 @@ static int stm32_adfsdm_pcm_new(struct snd_soc_component *component,
 static int stm32_adfsdm_dummy_cb(const void *data, void *private)
 {
 	/*
-	 * This dummmy callback is requested by iio_channel_get_all_cb() API,
+	 * This dummy callback is requested by iio_channel_get_all_cb() API,
 	 * but the stm32_dfsdm_get_buff_cb() API is used instead, to optimize
 	 * DMA transfers.
 	 */