realtek: rtl838x: add Netgear GS110TUP v1 support

realtek: rtl838x: add Netgear GS110TUP v1 support

The GS110TUP v1 is a managed switch similar to the GS110TPP v1, but with
port 10 as SFP instead of RJ-45 and a total budget of 240 watts. Ports
1-4 support 60-watt 802.3bt PoE and ports 5-8 support 30-watt 802.3at.

The flash layout of the two switches are identical, and the U-Boot
configurations are the same except for having a different magic number,
so installation can be done via the same U-Boot method.

The following command will be needed to enable the port LEDs as per
https://forum.openwrt.org/t/72510/51 :
    fw_setenv bootcmd "rtk network on; boota"

Additionally, port 9 (1000base-T from a separate QSGMII PHY) does not
function without this. Port 10 was not tested as no SFP module was
available.

Signed-off-by: Jacob Potter <jacob@j4cbo.com>
[rebase on merged flash layout]
Signed-off-by: Sander Vanheule <sander@svanheule.net>