[mlir][vector][spirv] Add SPIR-V lowering for `vector.to_elements`

[dcaballe]

Similar to the lowering to LLVM, we need to add the corresponding lowering to SPIR-V for vector.to_elements.

[llvmbot]

@llvm/issue-subscribers-mlir

Author: Diego Caballero (dcaballe)

Similar to the [lowering to LLVM](https://github.com//pull/145766), we need to add the corresponding lowering to SPIR-V for `vector.to_elements`.

[llvmbot]

@llvm/issue-subscribers-mlir-spirv

Author: Diego Caballero (dcaballe)

Similar to the [lowering to LLVM](https://github.com//pull/145766), we need to add the corresponding lowering to SPIR-V for `vector.to_elements`.