Fix minimal example to compile in Dev Board with Makefile

[jlz3008]

The Makefile for minimal example don't work in Dev Board with Mendel distro .
With this patch you can compile the minimal application but don't work with edgetpu models in Dev Board

mendel@undefined-dog:~/coral/edgetpu/src/cpp/examples$  LD_LIBRARY_PATH=/home/mendel/coral/edgetpu/libedgetpu/direct/aarch64 ./minimal ~/coral/edgetpu/test_data/mobilenet_v1_1.0_224_quant_edgetpu.tflite ~/coral/edgetpu/test_data/resized_cat.bmp 
ERROR: Internal: Unsupported data type in custom op handler: -610837120
ERROR: Node number 0 (edgetpu-custom-op) failed to prepare.

Failed to allocate tensors.
Segmentation fault

But works with tflite models

LD_LIBRARY_PATH=/home/mendel/coral/edgetpu/libedgetpu/direct/aarch64 ./minimal
 ~/coral/edgetpu/test_data/mobilenet_v1_1.0_224_quant.tflite ~/coral/edgetpu/test_data/resized_cat.bmp
[Image analysis] max value index: 286 value: 0.804688

The models works with python demos

mendel@undefined-dog:~/coral/tflite/python/examples/classification$ LD_LIBRARY_PATH=/home/mendel/coral/edgetpu/libedgetpu/direct/aarch64 python3 classify_image.py --model ~/coral/edgetpu/test_data/mobilenet_v1_1.0_224_quant_edgetpu.tflite --input  ~/coral/edgetpu/test_data/resized_cat.bmp 
----INFERENCE TIME----
Note: The first inference on Edge TPU is slow because it includes loading the model into Edge TPU memory.
14.6ms
2.3ms
2.3ms
2.3ms
2.3ms
-------RESULTS--------
286: 0.79297