Bluetooth: Add support for external configuration with UART driver

The quirk for enabling external configuration with UART needs to be
provided via the HCI UART flags. Add a new flag for it and declare
it as valid.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index a49ee1b4..401a3be 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -431,6 +431,9 @@
 	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 
+	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
+		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
+
 	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
 		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
 
@@ -482,7 +485,8 @@
 	unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
 				    BIT(HCI_UART_RESET_ON_INIT) |
 				    BIT(HCI_UART_CREATE_AMP) |
-				    BIT(HCI_UART_INIT_PENDING);
+				    BIT(HCI_UART_INIT_PENDING) |
+				    BIT(HCI_UART_EXT_CONFIG);
 
 	if ((flags & ~valid_flags))
 		return -EINVAL;