Bluetooth: hci_qca: get wakeup status from serdev device handle

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>