octeontx2-pf: Add support for ptp 1-step mode on CN10K silicon

Add support for ptp 1-step mode using timecounter. The seconds and
nanoseconds to be updated in PTP header are calculated by adding the
timecounter offset to the free running PTP clock counter time. The PF
driver periodically gets the PTP clock time using AF mbox. The 1-step
support uses HW feature to update correction field rather than
OriginTimestamp field in PTP header.

Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Naveen Mamindlapalli <naveenm@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>