MIPS: Hook up name_to_handle_at, open_by_handle_at and clock_adjtime syscalls.

These system calls we recently added.

32-bit ABIs need compat handling for sys_clock_adjtime().

o32 also needs compat handling for sys_open_by_handle_at();

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2165/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>