[FEA] Is it possible to support None dtype with tvm ffi?

[yingluosanqian]

Which component requires the feature?

CuTe DSL

Feature Request

Is your feature request related to a problem? Please describe.
I wish I could use CuTeDSL to impl the below kernel:

@cute.jit
def add_one(a: Optional[cute.Tensor]):
  ...

where a might be a cute.Tensor or just None.

After reading CuTeDSL docs, I found currently None dtype is not supported in CuTeDSL tmv ffi. Is it possible to support it?

Describe the solution you'd like
Support None dtype in cutedsl tmv ffi.

Describe alternatives you've considered
None.

Additional context
None.