am 3cd1a144: Set line discipline to HCI_UART_H4 even for low power mode.

Merge commit '3cd1a1440d74cc31be247f0bd967a432d26042ac'

* commit '3cd1a1440d74cc31be247f0bd967a432d26042ac':
  Set line discipline to HCI_UART_H4 even for low power mode.