net: add devm version of alloc_etherdev_mqs function

This patch adds devm_alloc_etherdev_mqs function and devm_alloc_etherdev
macro. These can be used for simpler netdev allocation without having to
care about calling free_netdev.

Thanks to this change drivers, their error paths and removal paths may
get simpler by a bit.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>