Minimize logs when loading a cheevos-compatible content

Minimize logs when loading a cheevos-compatible content

- Using retro_memory_descriptors[] for memmap creates a list of address for a game. At the moment, its quite long and can cover up the log window.
  Since there is only 1 pointer used, using the traditional retro_get_memory_map/data works enough for this purpose.

- Move the use of memory descriptors to debug build.