tests/bluetooth/init/bluetooth.init.test_ctlr_dbg fails to build on nrf51dk_nrf51422

[galak]

When running:

./scripts/sanitycheck -p nrf51dk_nrf51422 -s tests/bluetooth/init/bluetooth.init.test_ctlr_dbg

Fails:

[ 73%] Building C object zephyr/subsys/bluetooth/controller/CMakeFiles/subsys__bluetooth__controller.dir/ll_sw/ull.c.obj
/home/galak/git/zephyr/subsys/bluetooth/controller/ll_sw/ull.c:143:8: error: 'BT_SCAN_SYNC_TICKER_NODES' undeclared here (not in a function); did you mean 'BT_ADV_SYNC_TICKER_NODES'?
  143 |        BT_SCAN_SYNC_TICKER_NODES + \
      |        ^~~~~~~~~~~~~~~~~~~~~~~~~
/home/galak/git/zephyr/subsys/bluetooth/controller/ll_sw/ull.c:156:39: note: in expansion of macro 'TICKER_NODES'
  156 | static uint8_t MALIGN(4) ticker_nodes[TICKER_NODES][TICKER_NODE_T_SIZE];
      |                                       ^~~~~~~~~~~~
/home/galak/git/zephyr/subsys/bluetooth/controller/ll_sw/ull.c:156:26: error: 'ticker_nodes' defined but not used [-Werror=unused-variable]
  156 | static uint8_t MALIGN(4) ticker_nodes[TICKER_NODES][TICKER_NODE_T_SIZE];
      |                          ^~~~~~~~~~~~
cc1: all warnings being treated as errors