intel_idle: Use subsys_initcall_sync() for initialization

JIRA: https://issues.redhat.com/browse/RHEL-110839

commit c0f6913
Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Date:   Thu Jun 5 17:04:11 2025 +0200

    intel_idle: Use subsys_initcall_sync() for initialization

    It is not necessary to wait until the device_initcall() stage with
    intel_idle initialization.  All of its dependencies are met after
    all subsys_initcall()s have run, so subsys_initcall_sync() can be
    used for initializing it.

    It is also better to ensure that intel_idle will always initialize
    before the ACPI processor driver that uses module_init() for its
    initialization.

    Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
    Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
    Link: https://patch.msgid.link/2994397.e9J7NaK4W3@rjwysocki.net

Signed-off-by: Steve Best <sbest@redhat.com>

Author: sfbest

drivers/idle/intel_idle.c

@@ -2487,7 +2487,7 @@ static int __init intel_idle_init(void)
 	return retval;
 
 }
-device_initcall(intel_idle_init);
+subsys_initcall_sync(intel_idle_init);
 
 /*
  * We are not really modular, but we used to support that.  Meaning we also