intel_th: Constify the struct device_type usage

Since commit aed65af ("drivers: make device_type const"), the driver
core can properly handle constant struct device_type. Move the
intel_th_source_device_type, intel_th_output_device_type,
intel_th_switch_device_type and intel_th_device_type variables to be
constant structures as well, placing it into read-only memory which can not
be modified at runtime.

Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240429130119.1518073-7-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: rbmarliere

drivers/hwtracing/intel_th/core.c

@@ -180,7 +180,7 @@ static void intel_th_device_release(struct device *dev)
 	intel_th_device_free(to_intel_th_device(dev));
 }
 
-static struct device_type intel_th_source_device_type = {
+static const struct device_type intel_th_source_device_type = {
 	.name		= "intel_th_source_device",
 	.release	= intel_th_device_release,
 };
@@ -333,19 +333,19 @@ static struct attribute *intel_th_output_attrs[] = {
 
 ATTRIBUTE_GROUPS(intel_th_output);
 
-static struct device_type intel_th_output_device_type = {
+static const struct device_type intel_th_output_device_type = {
 	.name		= "intel_th_output_device",
 	.groups		= intel_th_output_groups,
 	.release	= intel_th_device_release,
 	.devnode	= intel_th_output_devnode,
 };
 
-static struct device_type intel_th_switch_device_type = {
+static const struct device_type intel_th_switch_device_type = {
 	.name		= "intel_th_switch_device",
 	.release	= intel_th_device_release,
 };
 
-static struct device_type *intel_th_device_type[] = {
+static const struct device_type *intel_th_device_type[] = {
 	[INTEL_TH_SOURCE]	= &intel_th_source_device_type,
 	[INTEL_TH_OUTPUT]	= &intel_th_output_device_type,
 	[INTEL_TH_SWITCH]	= &intel_th_switch_device_type,