The PTP core indicates in system_device_crosststamp::clock_id the clock ID for which the system time stamp should be taken. That allows to utilize hardware timestamps with e.g. AUX clocks. Save the provided clock ID and use it in igc_phc_get_syncdevicetime() for taking the history snapshot. No functional change. Signed-off-by: Thomas Gleixner <tglx@kernel.org> Tested-by: Arthur Kiyanovski <akiyano@amazon.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Link: https://patch.msgid.link/20260529195557.637381831@kernel.org