ARC: reuse headers for both ARCv3 and ARCv3 if possible

Reuse ARCv2 headers [where it is possible] for ARCv3.
In this commit we simply allow to use them for ARCv3, we'll
move it to proper folder and rename them [where it is required]
in the upcoming cleanup patch.

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