MIPS: backport seccomp filter support & dependencies

This patch contains the following commits backported
from upstream and squashed :

22feadbe MIPS: asm: syscall: Add the syscall_rollback function
51d139b1 MIPS: Enable entries for SIGSYS in struct siginfo.
490b004f MIPS: Select HAVE_ARCH_SECCOMP_FILTER
4c21b8fd MIPS: seccomp: Handle indirect system calls (o32)
1225eb82 MIPS: ptrace: Move away from secure_computing_strict
6e345746 MIPS: asm: syscall: Define syscall_get_arch
1d7bf993 MIPS: ftrace: Add support for syscall tracepoints.
bec9b2b2 MIPS: Move audit_arch() helper function to __syscall_get_arch().
0dfa95aa MIPS: ptrace: Switch syscall reporting to tracehook_report_syscall_entry().
bc3d22c1 MIPS: ptrace: Use tracehook helpers.
7aeb753b MIPS: Implement task_user_regset_view.
f925725d mips: unobfuscate _TIF..._MASK
e7f3b48a MIPS: Cleanup flags in syscall flags handlers.
9d37c405 MIPS: kernel: scalls: Skip the syscall if denied by the seccomp filter
c0ff3c53 MIPS: Enable HAVE_ARCH_TRACEHOOK.
6a9c001b MIPS: Switch ELF core dumper to use regsets.
19e2e172 MIPS: Provide arch_syscall_addr.

Change-Id: Idd8030f6136c28d41d9a45a0a5b4e76587a302bc
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>