Revert "net: phy: mscc: macsec: reject PN update requests"

This reverts commit 935a1533 which is
commit e0a8c918 upstream.

It breaks the Android KABI and is not needed at this time for any
Android-relevant systems.

Bug: 161946584
Change-Id: Icc2bb21cc8f1432d765a4fbf279fdcd5ffffd281
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>