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>