Merge branch 'mlx5e-tstamp'

Saeed Mahameed says:

====================
Introduce mlx5 ethernet timestamping

This patch series introduces the support for ConnectX-4 timestamping
and the PTP kernel interface.

Changes from V2:
net/mlx5_core: Introduce access function to read internal_timer
	- Remove one line function
	- Change function name

net/mlx5e: Add HW timestamping (TS) support:
	- Data path performance optimization (caching tstamp struct in rq,sq)
	- Change read/write_lock_irqsave to read/write_lock
	- Move ioctl functions to en_clock file
	- Changed overflow start algorithm according to comments from Richard
	- Move timestamp init/cleanup to open/close ndos.

In details:

1st patch prevents the driver from modifying skb->data and SKB CB in
device xmit function.

2nd patch adds the needed low level helpers for:
	- Fetching the hardware clock (hardware internal timer)
	- Parsing CQEs timestamps
	- Device frequency capability

3rd patch adds new en_clock.c file that handles all needed timestamping
operations:
	- Internal clock structure initialization and other helper functions
	- Added the needed ioctl for setting/getting the current timestamping
	  configuration.
	- used this configuration in RX/TX data path to fill the SKB with
	  the timestamp.

4th patch Introduces PTP (PHC) support.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>