net: atlantic: fix PTP on AQC10X

This patch fixes PTP on AQC10X.
PTP support on AQC10X requires FW involvement and FW configures the
TPS data arb mode itself.
So we must make sure driver doesn't touch TPS data arb mode on AQC10x
if PTP is enabled. Otherwise, there are no timestamps even though
packets are flowing.

Fixes: 2deac71a ("net: atlantic: QoS implementation: min_rate")
Signed-off-by: Egor Pomozov <epomozov@marvell.com>
Signed-off-by: Mark Starovoytov <mstarovoitov@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>