ARM: add seccomp syscall

Wires up the new seccomp syscall.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Lee Campbell <leecam@chromium.org>
Git-commit: a9ba4285aa5722a3b4d84888e78ba8adc0046b28
Git-repo: https://www.codeaurora.org/cgit/external/gigabyte/kernel/msm


[rsiddoji@codeaurora.org: resolve trivial merge conflicts]

Change-Id: I14dfb81ae5b470f0c8fa4d6420c9e63c3e8b240b
Signed-off-by: Ravi Kumar Siddojigari <rsiddoji@codeaurora.org>