[mlir][tosa] Fix tosa.mul to use tosa.apply_scale

Multiply-shift requires wider compute types or CPU specific code to avoid
premature truncation, apply_shift fixes this issue

Also, Tosa's mul op supports different input / output types. Added path that
sign-extends input values to int-32 values before multiplying.

Differential Revision: https://reviews.llvm.org/D99011