Syscalls: Update list for 6.11

The generic syscall table has different names for syscalls that take a
timespec64 on 32-bit targets, in that it adds the `_time64` suffix.
Similarly, the `_time32` suffix has been removed.

I'm not sure if the existing logic for determining the proper timespec
struct to use was subtly broken, but it should be a good chance to
finish ziglang#4726 - we only have 14 years after all...

In other news:

- x86_64 gets `uretprobe`, a syscall to speed up returning BPF probes.
- Hexagon gets `clone3`, but don't be fooled: it just returns ENOSYS.