ice: stop destroying and reinitalizing Tx tracker during reset

The ice driver currently attempts to destroy and re-initialize the Tx
timestamp tracker during the reset flow. The release of the Tx tracker
only happened during CORE reset or GLOBAL reset. The ice_ptp_rebuild()
function always calls the ice_ptp_init_tx function which will allocate
a new tracker data structure, resulting in memory leaks during PF reset.

Certainly the driver should not be allocating a new tracker without
removing the old tracker data, as this results in a memory leak.
Additionally, there's no reason to remove the tracker memory during a
reset. Remove this logic from the reset and rebuild flow. Instead of
releasing the Tx tracker, flush outstanding timestamps just before we
reset the PHY timestamp block in ice_ptp_cfg_phy_interrupt().

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Karol Kolacinski <karol.kolacinski@intel.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>