mlir_aie_mem_alloc assumes DWORDS

[denolf]

Tutorial 5 https://github.com/Xilinx/mlir-aie/blob/tutorial/tutorials/tutorial-5/test.cpp#L55-#L56 uses mlir_aie_mem_alloc to allocated memory in DRAM. It is implicitly assumed DWORDS (int) are being allocated, while malloc typically allocates bytes.

Due to AIE alignment restriction, we most likely need 32b (or maybe an even coarser alignment)?