ARC: LIB: add ARC MWDT libc support

ARC MWDT toolchain doesn't provide newlib, let's add support
of ARC MWDT libc to Zephyr

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