[net-next 0/4] remove deprecated syststamp

[Willem de Bruijn <willemb@google.com>]

The network stack can generate two kinds of hardware timestamps:
- hwtstamp stores a hw timestamp in device-specific raw format
- syststamp convers the raw format to system time

The second is deprecated and only implemented by a single device
driver. The suggested alternative is to communicate hwtstamp +
directly expose the NIC PTP clock device through ptp_clock_info.
The remaining driver (octeon) does not expose such a standard
interface as of now. It does have its own PTP library that depends
on its own shared memory PTP clock interface.

This patchset
1. reverts the syststamp code in the one driver (octeon)
2. reverts an unnecessary zero initialization in another (vxge)
3. modifies PF_PACKET to use syststamp is != 0 (because always == 0)
4. modifies SCM_TIMESTAMPING in the same way

For backwards compatibility, the interfaces are not removed.
Applications can still request SOF_TIMESTAMPING_SYS_HARDWARE. The
response field in scm_timestamping also remains. As was the case
for hardware/drivers that did not implement the feature, the
setsockopt succeeds, but the response field is always zero.

-- 
2.0.0.526.g5318336