net/octeontx2: fix PTP enable via Rx offload flags

net/octeontx2: fix PTP enable via Rx offload flags

Earlier implementation for enabling ptp via RX offload flag was
causing segmentation fault as it was getting executed in the
device configuration stage where RX and TX queues were not
configured. As in the ptp enable process rx queues are used for
mbuf setup while tx queues are used for send descriptor setup.
Moving the logic in dev start as all the resources will be
configured.

Fixes: b5dc3140448e ("net/octeontx2: support base PTP")

Signed-off-by: Harman Kalra <hkalra@marvell.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>