fix sdl2 map

[s88100]

• fixed map, if font size is set to small, is similar to https://github.com/draconisPW/PWMAngband/blob/c5501ffdc4df87df5756547d57d2631b91f69fab/src/client/main-win.c#L2313-L2323 Setup.max_row, Setup.max_col for map_info(), player->scr_info[y][x]

  V code:
  term_view_map_tile()
  int w = tile.w * cave->width;
  int h = tile.h * cave->height;
  . . . . .
  for (int y = 0; y < cave->height; y++) {
  tile.y = y * tile.w;
  for (int x = 0; x < cave->width; x++) {
      tile.x = x * tile.h;
      render_grid_cell_tile(subwindow, map, tile, x, y);
  }
  }

• check (a & 0x80) is similar to https://github.com/draconisPW/PWMAngband/blob/c5501ffdc4df87df5756547d57d2631b91f69fab/src/client/main-sdl.c#L5638-L5642 fixed