[Util] start working on numpy_to_hls_code

src/finn/backend/fpgadataflow/utils.py

+from finn.core.utils import pack_innermost_dim_as_hex_string
+
+
+def numpy_to_hls_code(ndarray, dtype, pack_innermost_dim=True):
+    hls_dtype = dtype.get_hls_datatype_str()
+    if pack_innermost_dim:
+        idimlen = ndarray.shape[-1]
+        ndarray = pack_innermost_dim_as_hex_string(ndarray, dtype, idimlen)
+        hls_dtype = "ap_uint<%d>" % (idimlen * dtype.bitwidth())
+    return hls_dtype