ASoC: Intel: avs: Add missing includes

The debugfs file utilizes string helpers such as parse_int_array_user()
yet does not include the header.

Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://patch.msgid.link/20250109122216.3667847-14-cezary.rojewski@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: crojewsk-intel

sound/soc/intel/avs/debugfs.c

@@ -10,6 +10,7 @@
 #include <linux/kfifo.h>
 #include <linux/wait.h>
 #include <linux/sched/signal.h>
+#include <linux/string_helpers.h>
 #include <sound/soc.h>
 #include "avs.h"
 #include "messages.h"