Bluetooth: hci_serdev: Close UART port if NON_PERSISTENT_SETUP is set

When HCI_QUIRK_NON_PERSISTENT_SETUP is set by drivers,
it indicates that BT SoC will be completely powered OFF
during BT OFF. On next BT ON firmware must be downloaded
again. Holding UART port open during BT OFF is draining
the battery. Now during BT OFF, UART port is closed if
qurik HCI_QUIRK_NON_PERSISTENT_SETUP is set by clearing
HCI_UART_PROTO_READY proto flag. On next BT ON, UART
port is opened if HCI_UART_PROTO_READY proto flag is cleared.

Signed-off-by: Venkata Lakshmi Narayana Gubba <gubbaven@codeaurora.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>