ice: Cache perout/extts requests and check flags

Cache original PTP GPIO requests instead of saving each parameter in
internal structures for periodic output or external timestamp request.

Factor out all periodic output register writes from ice_ptp_cfg_clkout
to a separate function to improve readability.

Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: Karol Kolacinski <karol.kolacinski@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>