net: lan743x: Remove duplicate check

Since timespec64_valid() has been checked in higher layer
pc_clock_settime(), the duplicate check in lan743x_ptpci_settime64()
can be removed.

Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://patch.msgid.link/20241009072302.1754567-3-ruanjinjie@huawei.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>