ARC: allow to build code for processors without ZOL

ARCv3 64 bit processors doesn't have Zero Delay Loop
(also named Zero Overhead Loop, ZOL) mechanism. Add kconfig
option to remove ZOL register save/restore so the code
can be build for both ARCv2 and ARCv3.

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