MLECO-2345: Adding dynamic load support for FVPs

With this patch, the generic inference runner use-case can be
configured to accept the model tflite file at run-time via
the FVP's command line parameters. Same is true for the IFM
and the inference results can be dumped out too.

NOTE: this change is only for supporting the FVP, the FPGA
implementation will not allow additional loading for the
changes in this patch to be useful.

Change-Id: I1318bd5b0cfb7bb635ced6fe58d22c3e401d2547