ASoC: Intel: fix possible acpi enumeration panic

A crash can occur on some platforms where adsp is enumerated but codec is not
matched. Define codec_id as a pointer intead of an array so that it gets
initialized to NULL for the terminating element of sst_acpi_bytcr[] and
sst_acpi_chv[].

Signed-off-by: Kevin Strasser <kevin.strasser@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/sst/sst_acpi.c

@@ -43,7 +43,7 @@
 #include "sst.h"
 
 struct sst_machines {
-	char codec_id[32];
+	char *codec_id;
 	char board[32];
 	char machine[32];
 	void (*machine_quirk)(void);