Some symbols are deprecated or have been removed by Nordic. Other things generate some
errors because of configuration mistakes.
CONFIG_BT_BUF_EVT_RX_COUNT needs to be larger than CONFIG_BT_BUF_ACL_TX_COUNTBT_BUF_H4 has been removed:
bt_buf_type_from_h4(h4_type, BT_BUF_OUT)