realtek: netgear-gigabit: Enable RTL8231

Since the move to 5.10, there are now two GPIO drivers. The gpio0 node
refers to the internal GPIOs, so the indirect-access-bus-id is no longer
relevant for that node.

Set indirect-access-bus-id to the correct value (31) on the correct node
(gpio1) and enable the device.

Cc: Raylynn Knight <rayknight@me.com>
Cc: Michael Mohr <akihana@gmail.com>
Cc: Stijn Segers <foss@volatilesystems.org>
Cc: Stijn Tintel <stijn@linux-ipv6.be>
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Tested-by: Bjørn Mork <bjorn@mork.no>