octeontx2-nicvf: Add PTP hardware clock support to NIX VF

This patch adds PTP PHC support to NIX VF interfaces. This enables
a VF to run PTP master/slave instance. PTP block being a shared
hardware resource it is recommended to avoid running multiple
PTP instances in the system which will impact the PTP clock
accuracy.

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