ls2088 ddr tfa init for 2 controllers

[LZG]

Problem description：

     ls2088ardb has two ddr controllers, but the initial configuration of ddr in the code is using the same parameter configuration, there are two problems in this case:
    1. Can you use two different parameters (different hardware pcb leads to different parameter timing) to configure two ddr controllers respectively
   2, If feasible, how should I modify

  Use nodimm to configure.

Initializes the code path：ls2088ardb/ddr_init.c

[yipingwang]

For nodimm DDR configuration, please refer to plat/nxp/soc-ls1043a/ls1043ardb/ddr_init.c.

Please modify the following section according to your custom board.
zeromem(&info, sizeof(struct ddr_info));
info.num_ctlrs = 1;
info.dimm_on_ctlr = 1;
info.clk = get_ddr_freq(&sys, 0);
info.ddr[0] = (void *)NXP_DDR_ADDR;

dram_size = dram_init(&info);