As a preparation to ARCv2 port submission we rename "arc700" folder to
"arcv1" which stands for ARCv1 ISA also known as ARCompact.

This will allow us to add more flavours of binary-compatible ARCv1 CPUs
like ARC600 if needed later on and all required ARCv2 CPUs (which are
binary incompatible with ARCv1) in "arcv2" folder in subsequent commits.
Signed-off-by: NAlexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: NIgor Guryanov <guryanov@synopsys.com>