clocksource/drivers/timer-ti-dm: Fix child node refcount handling

of_find_compatible_node() increments the node's refcount, and it must be
decremented again with a call to of_node_put() when the pointer is no
longer required to avoid leaking the resource.

Instead of adding the missing calls to of_node_put() in all execution
paths, use the cleanup attribute for 'arm_timer' by means of the
__free() macro, which automatically calls of_node_put() when the
variable goes out of scope.

Fixes: 25de4ce ("clocksource/drivers/timer-ti-dm: Handle dra7 timer wrap errata i940")
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20241031-timer-ti-dm-systimer-of_node_put-v3-1-063ee822b73a@gmail.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Author: javiercarrascocruz

drivers/clocksource/timer-ti-dm-systimer.c

@@ -686,9 +686,9 @@ subsys_initcall(dmtimer_percpu_timer_startup);
 
 static int __init dmtimer_percpu_quirk_init(struct device_node *np, u32 pa)
 {
-	struct device_node *arm_timer;
+	struct device_node *arm_timer __free(device_node) =
+		of_find_compatible_node(NULL, NULL, "arm,armv7-timer");
 
-	arm_timer = of_find_compatible_node(NULL, NULL, "arm,armv7-timer");
 	if (of_device_is_available(arm_timer)) {
 		pr_warn_once("ARM architected timer wrap issue i940 detected\n");
 		return 0;