timerfd: arch, arm -- Add sys_timerfd related syscalls

This is required to support checkpoint and restore of timers
that notify via file descriptors on ARM and AArch64.
Signed-off-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

arch/arm/syscall.def

@@ -79,12 +79,14 @@ timer_settime			110	258	(timer_t timer_id, int flags, const struct itimerspec *n
 timer_gettime			108	259	(int timer_id, const struct itimerspec *setting)
 timer_getoverrun		109	260	(int timer_id)
 timer_delete			111	261	(timer_t timer_id)
+clock_gettime			113	263	(const clockid_t which_clock, const struct timespec *tp)
 exit_group			94	248	(int error_code)
 set_robust_list			99	338	(struct robust_list_head *head, size_t len)
 get_robust_list			100	339	(int pid, struct robust_list_head **head_ptr, size_t *len_ptr)
 signalfd4			74	355	(int fd, k_rtsigset_t *mask, size_t sizemask, int flags)
 rt_tgsigqueueinfo		240	363	(pid_t tgid, pid_t pid, int sig, siginfo_t *info)
 vmsplice			75	343	(int fd, const struct iovec *iov, unsigned long nr_segs, unsigned int flags)
+timerfd_settime			86	353	(int ufd, int flags, const struct itimerspec *utmr, struct itimerspec *otmr)
 fanotify_init			262	367	(unsigned int flags, unsigned int event_f_flags)
 fanotify_mark			263	368	(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname)
 open_by_handle_at		265	371	(int mountdirfd, struct file_handle *handle, int flags)