You should add your table to arch/arm/mach-tegra/board-ardbeg-memory.c
Create another instance of tegra12_emc_table and initialize it with your table.
The code loads the correct table by looking at the board id - assuming you have added a new board id, you should add a case for it and load your table accordingly. If not, load your new table by some other means like overwriting the default PM375 table (unrecommended).
BR,
Michael