Add hardware breakpoint ptrace test

This adds a ptrace test which tests the hardware breakpoint
functionality of the ptrace api.

I've also renamed the test case to sys_ptrace to better match the naming
scheme in the other files. I've ran the tests on angler (32 and 64 bit)
and fugu.

Test: run the test
Change-Id: I7d8a7d79585477d78da1f033c85f8d2cc3b34340