net: ethernet: ti: am65-cpts: adjust estf following ptp changes

When the CPTS clock is synced/adjusted by running linuxptp (ptp4l/phc2sys),
it will cause the TSN EST schedule to drift away over time. This is because
the schedule is driven by the EstF periodic counter whose pulse length is
defined in ref_clk cycles and it does not automatically sync to CPTS clock.
   _______
 _|
  ^
  expected cycle start time boundary
   _______________
 _|_|___|_|
  ^
  EstF drifted away -> direction

To fix it, the same PPM adjustment has to be applied to EstF as done to the
PHC CPTS clock, in order to correct the TSN EST cycle length and keep them
in sync.

Drifted cycle:
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635968230373377017
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635968230373877017
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635968230374377017
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635968230374877017
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635968230375377017
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635968230375877023
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635968230376377018
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635968230376877018
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635968230377377018

Stable cycle:
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635966863193375473
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635966863193875473
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635966863194375473
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635966863194875473
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635966863195375473
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635966863195875473
AM65_CPTS_EVT: 7 e1:01770001 e2:000000ff t:1635966863196375473

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Link: https://lore.kernel.org/r/20230321062600.2539544-1-s-vadapalli@ti.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>