net: ethernet: stmicro: stmmac: first disable all queues and disconnect in release

Disable all queues and disconnect before tx_disable in stmmac_release to
prevent a corner case where packet may be still queued at the same time
tx_disable is called resulting in kernel panic if some packet still has
to be processed.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>