[U-Boot] how to include the get_ram_size() function on mpc8323erdb.c souce

I have seen that for the mpc8323e bsp, the RAM memory is just defined as 64Mb by means to set the MPC8323ERDB.h. I would like to use the get_ram_size() function found in memsize.c source by including it on the mpc8323erdb. source. Could anyone tell me what is the procedure to make this modification? I.e, what should I do to get the mem verification working on my system?

Thanks and best regards