rknn-toolkit-lite2 dose not support data_format=['nchw']

[Lu-tju]

In rknn-toolkit2, it works well:

outputs = rknn.inference(inputs=[img_norm], data_format=['nchw'])

but in rknn-toolkite-lite2, there is a error as:

self.rknn_runtime.set_inputs(inputs, data_type, data_format, inputs_pass_through=inputs_pass_through)
File "rknnlite/api/rknn_runtime.py", line 1008, in rknnlite.api.rknn_runtime.RKNNRuntime.set_inputs
KeyError: 'nchw'