Merge branch 'stmmac-ptp'

Xiaoliang Yang says:

====================
net: stmmac: re-configure tas basetime after ptp time adjust

If the DWMAC Ethernet device has already set the Qbv EST configuration
before using ptp to synchronize the time adjustment, the Qbv base time
may change to be the past time of the new current time. This is not
allowed by hardware.

This patch calculates and re-configures the Qbv basetime after ptp time
adjustment.

v1->v2:
  Update est mutex lock to protect btr/ctr r/w to be atomic.
  Add btr_reserve to store basetime from qopt and used as origin base
time in Qbv re-configuration.
====================

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