net: atlantic: changes for multi-TC support

This patch contains the following changes:
* add cfg->is_ptp (used for PTP enable/disable switch, which
  is described in more details below);
* add cfg->tc_mode (A1 supports 2 HW modes only);
* setup queue to TC mapping based on TC mode on A2;
* remove hw_tx_tc_mode_get / hw_rx_tc_mode_get hw_ops.

In the first generation of our hardware (A1), a whole traffic class is
consumed for PTP handling in FW (FW uses it to send the ptp data and to
send back timestamps).
The 'is_ptp' flag introduced in this patch will be used in to automatically
disable PTP when a conflicting configuration is detected, e.g. when
multiple TCs are enabled.

Signed-off-by: Dmitry Bezrukov <dbezrukov@marvell.com>
Co-developed-by: Mark Starovoytov <mstarovoitov@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>