Merge branch 'ptp-adjphase-cleanups'

Rahul Rameshbabu says:

====================
ptp .adjphase cleanups

The goal of this patch series is to improve documentation of .adjphase, add
a new callback .getmaxphase to enable advertising the max phase offset a
device PHC can support, and support invoking .adjphase from the testptp
kselftest.

Changes:
  v2->v1:
    * Removes arbitrary rule that the PHC servo must restore the frequency
      to the value used in the last .adjfine call if any other PHC
      operation is used after a .adjphase operation.
    * Removes a macro introduced in v1 for adding PTP sysfs device
      attribute nodes using a callback for populating the data.

Link: https://lore.kernel.org/netdev/20230120160609.19160723@kernel.org/
Link: https://lore.kernel.org/netdev/20230510205306.136766-1-rrameshbabu@nvidia.com/
====================

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