[tosa_mlir_translator] Fix deprecated casts

Refactor to remove .cast<T>, .dyn_cast<T> and .isa<T> deprecated
functions, and replaced with mlir::cast<T>, mlir::dyn_cast<T> and mlir::isa<T>

Signed-off-by: Tai Ly <tai.ly@arm.com>
Change-Id: I1432be64a0888ab296a8d8acd8320f22b68cc1ec