Revert "net: phy: improve mdiobus_stats_acct"

This reverts commit 1afccc5a201ec7c9023370958bae1312369b64da.

As reported by Marek the change causes a warning on non-PREEMPT_RT
32 bit systems.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://patch.msgid.link/c3a1aba9-3fae-4c4b-bcb1-fb620fb7a309@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>