mlxsw: Initialize txhdr_info according to PTP operations

mlxsw: Initialize txhdr_info according to PTP operations

A next patch will construct Tx header as part of pci.c. The switch driver
(mlxsw_spectrum.ko) should encapsulate all the differences between the
different ASICs and the bus driver (mlxsw_pci.ko) should remain unaware.

As preparation, add the relevant info as part of mlxsw_txhdr_info
structure, so later bus driver will merely construct the Tx header based on
information passed from the switch driver.

Most of the packets are transmitted as control packets, but PTP packets in
Spectrum-2 and Spectrum-3 should be handled differently. The driver
transmits them as data packets, and the default VLAN tag (4095) is added if
the packet is not already tagged.

Extend PTP operations to store a boolean which indicates whether packets
should be transmitted as data packets. Set it for Spectrum-2 and
Spectrum-3 only. Extend mlxsw_txhdr_info to store fields which will be used
later to construct Tx header. Initialize such fields according to the new
boolean which is stored in PTP operations.

Note that for now, mlxsw_txhdr_info structure is initialized, but not used,
a next patch will use it.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Link: https://patch.msgid.link/efcaacd4bedef524e840a0c29f96cebf2c4bc0e0.1737044384.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>