ASoC: SDCA: Add comment for function reset polling

Add a comment to better explain the function reset polling rate.

Tested-by: Bard Liao <[e-mail]>
Reviewed-by: Maciej Strozek <[e-mail]>
Reviewed-by: Peter Ujfalusi <[e-mail]>
Tested-by: Richard Fitzgerald <[e-mail]>
Signed-off-by: Charles Keepax <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Reviewed-by: Vinod Koul <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/sdca/sdca_fdl.c

···
 		return -EINVAL;
 	}
 
+	/*
+	 * Poll up to 16 times but no more than once per ms, these are just
+	 * arbitrarily selected values, so may be fine tuned in future.
+	 */
 	poll_us = umin(function->reset_max_delay >> 4, 1000);
 
 	ret = regmap_read_poll_timeout(regmap, reg, val, !val, poll_us,