`NormalizeIntensity` docstring error

[yiheng-wang-nv]

docstring of channel_wise is wrong, and it may mislead users that this parameter only works when subtrahend and divisor are not provided.

[Nic-Ma]

Hi @yiheng-wang-nv ,

Sorry for the wrong description of channel_wise arg, I will try to correct it ASAP.

Thanks.