Revert "net: stmmac: Enable mac_managed_pm phylink config"

This reverts commit 67a03645 which is
commit f151c147 upstream.

It breaks the Android kernel build and is not needed as part of the
normal Android GKI kernel build, so can be safely reverted.

Bug: 161946584
Change-Id: I4abf5fd61b9e23baa5103e41afdb1f12806b779b
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>