Bluetooth: Respect HCI_UART_DEBUG config in hci_ll.c

Following the pattern from hci_*.c, turn off BT_DBG messages unless
they have been requested via HCI_UART_DEBUG

Signed-off-by: Nick Pelly <npelly@google.com>
Acked-by: Brian Swetland <swetland@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
index b91d45a..2d2f66e 100644
--- a/drivers/bluetooth/hci_ll.c
+++ b/drivers/bluetooth/hci_ll.c
@@ -51,6 +51,11 @@
 
 #include "hci_uart.h"
 
+#ifndef CONFIG_BT_HCIUART_DEBUG
+#undef  BT_DBG
+#define BT_DBG( A... )
+#endif
+
 /* HCILL commands */
 #define HCILL_GO_TO_SLEEP_IND	0x30
 #define HCILL_GO_TO_SLEEP_ACK	0x31