ARC: MWDT: use LLVM C++ library instead of MWDT one

The MWDT toolchain provides two C++ libraries. Let's use
LLVM C++ library.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Evgeniy Paltsev <PaltsevEvgeniy@gmail.com>
1 file changed