[mlir][acc] Clean up TypedValue builders (#126968)
When MappableType was introduced alongside PointerLikeType, the data
clause operation builders were duplicated to accept a `TypedValue` of
one of the two type options. However, the underlying builder takes a
`Value` and this difference is not relevant for it. The only difference
is that `varType` is set differently depending on the type.
Having two duplicated builders can lead to clunky building since a
`Value` must always be cast to one of the two options. Thus, simply
clean this up - the verifier already checks that it is a type that
implements one of the two interfaces.
