mem_map_from_dram_banks calls fdtdec_setup_memory_banksize to setup the
dram banks though that is expected to be done by dram_init_banksize as
part of board_r sequence.
This has the side effect of modifying gd->bd->bi_dram as well, therefore
this patch removes the call and updates spl_enable_cache for K3 to call
dram_init_banksize.