ice: Remove unnecessary ice_is_e8xx() functions

Remove unnecessary ice_is_e8xx() functions and PHY model. Instead, use
MAC type where applicable.

Don't check device type in ice_ptp_maybe_trigger_tx_interrupt(), because
in reality it depends on the ready bitmap, which only E810 does not
have.

Call ice_ptp_cfg_phy_interrupt() unconditionally, because all further
function calls check the MAC type anyway and this allows simpler code
in the future with addition of the new MAC types.

Reorder ICE_MAC_* cases in switches in ice_ptp* as in enum ice_mac_type.

Signed-off-by: Karol Kolacinski <karol.kolacinski@intel.com>
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>