Bluetooth: hci_qca: only assign wakeup with serial port support

Only assign hdev->wakeup if the serial port supports wakeup. Otherwise
it will fall back to the hci_uart_wakeup or the behavior that can be
overridden before calling the hci_uart_register_device().

Signed-off-by: Zhengping Jiang <jiangzp@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>