platform/x86: thinkpad_acpi: Take mutex in hotkey_resume

hotkey_status_set expects the hotkey_mutex to be held.
It seems like it was missed here and that gives lockdep
warnings while resuming.

Fixes: 38831eaf ("platform/x86: thinkpad_acpi: use lockdep annotations")
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Dennis Bonke <admin@dennisbonke.com>
Link: https://lore.kernel.org/r/20230914130356.235912-1-admin@dennisbonke.com


Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>