ptp_pch: Use ioread64_hi_lo() / iowrite64_hi_lo()

There is already helper functions to do 64-bit I/O on 32-bit machines or
buses, thus we don't need to reinvent the wheel.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220207210730.75252-3-andriy.shevchenko@linux.intel.com


Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>