ARC: gcc-m-cpu: check for exact HS CPU time instead of whole family

As of today we check against CPU_ARCHS config option which may be
related to different HS CPUs (i.e. ARCv2 HS, ARCv3 HS, etc...).
Let's check against exact HS CPU type (CPU_HS3X) as we do EM
processors.

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