Bluetooth: hci_uart: Update version number driver

This version number is more cosmetic and for debugging purposes, but
since there has been a few changes lately, increase it now.

Two left-over and not used version constants that were never exposed
anywhere are removed since they have no actual value.

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 19d0960..b265abc 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -46,7 +46,7 @@
 
 #include "hci_uart.h"
 
-#define VERSION "2.2"
+#define VERSION "2.3"
 
 static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];