Fix hardcoded mmap offset
mmap offset must be a multiple of the page size. It was hardcoded
to 4K, so mmap2 test failed on non-4K page size architectures.
Now we get page size using sysconf(_SC_PAGE_SIZE).
Build and run tests done on nsim arc hs38.
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>