platform/surface: acpi-notify: add WQ_PERCPU to alloc_workqueue users

This continues the effort to refactor workqueue APIs, which began with
the introduction of new workqueues and a new alloc_workqueue flag in:

   commit 128ea9f ("workqueue: Add system_percpu_wq and system_dfl_wq")
   commit 930c2ea ("workqueue: Add new WQ_PERCPU flag")

The refactoring is going to alter the default behavior of
alloc_workqueue() to be unbound by default.

With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU. For more details see the Link tag below.

In order to keep alloc_workqueue() behavior identical, explicitly request
WQ_PERCPU.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://lore.kernel.org/all/20250221112003.1dSuoGyc@linutronix.de/
Link: https://patch.msgid.link/20251127144125.233728-2-marco.crivellari@suse.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Author: DispatchCode

drivers/platform/surface/surface_acpi_notify.c

@@ -862,7 +862,7 @@ static int __init san_init(void)
 {
 	int ret;
 
-	san_wq = alloc_workqueue("san_wq", 0, 0);
+	san_wq = alloc_workqueue("san_wq", WQ_PERCPU, 0);
 	if (!san_wq)
 		return -ENOMEM;
 	ret = platform_driver_register(&surface_acpi_notify);