Use xxd -i to replace iree_c_embed_data in iree_model_input

Use "xxd -i" to replace iree_c_embed_data in iree_model_input. As a result, malloc and memcpy
on input buffers can be avoided. This also enable a future scenario of
using sensor inputs.

Change-Id: Ia378f21bc48cd2341f9b181ea627d7123e5fb01e