Bluetooth controller attached via the UART is handled by the serdev driver.
Get the wakeup status from the device handle through serdev, instead of the
parent path.

Fixes: c1a74160 ("Bluetooth: hci_qca: Add device_may_wakeup support")
Signed-off-by: Zhengping Jiang <jiangzp@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>