platform/chrome: cros_ec: Unregister notifier in cros_ec_unregister()

platform/chrome: cros_ec: Unregister notifier in cros_ec_unregister()

commit e2374953461947eee49f69b3e3204ff080ef31b1 upstream.

The blocking notifier is registered in cros_ec_register(); however, it
isn't unregistered in cros_ec_unregister().

Fix it.

Fixes: 42cd0ab476e2 ("platform/chrome: cros_ec: Query EC protocol version if EC transitions between RO/RW")
Cc: stable@vger.kernel.org
Reviewed-by: Benson Leung <bleung@chromium.org>
Link: https://lore.kernel.org/r/20250722120513.234031-1-tzungbi@kernel.org
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>