Revert "net: ethernet: ti: am65-cpsw: retain PORT_VLAN_REG after suspend/resume"

This reverts commit 643cf0e3.

This is to make it easier to revert the offending commit
fd23df72

 ("net: ethernet: ti: am65-cpsw: Add suspend/resume support")

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