realtek: reset both ethernet NIC and queues

Recent versions of Realtek's SDK reset both the ethernet NIC and queues
(SW_NIC_RST and SW_Q_RST bits) when initialising the hardware.

Furthermore, when issuing a CPU reset on the Zyxel GS1900-8 (not
supported by any current driver), the networking part of the SoC is not
reset. This leads to unresponsive network after the restart. By
resetting both the ethernet NIC and queues, networking always comes up
reliably.

Suggested-by: Birger Koblitz <mail@birger-koblitz.de>
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Tested-by: Stijn Tintel <stijn@linux-ipv6.be>