[mlir] tosa: build error when building with clang

The change of https://reviews.llvm.org/D121513#3411651
has caused a build error when building with clang:

/mnt/vss/_work/1/llvm-project/mlir/lib/Dialect/Tosa/IR/TosaOps.cpp:599:26: error: extra ';' outside of a function is incompatible with C++98 [-Werror,-Wc++98-compat-extra-semi]
ReduceFolder(ReduceAllOp);

Reviewed By: hpmorgan, Mogball

Differential Revision: https://reviews.llvm.org/D122599