realtek: add support for Hasivo S1100W-8XGT-SE switch

realtek: add support for Hasivo S1100W-8XGT-SE switch

This commit adds support for Hasivo S1100W-8XGT-SE switch.

Device specification
--------------------
SoC Type:	RTL9303
RAM:		Samsung K4B461646E-BYKO (512MB)
Flash:		Fudan FM25Q128A (16 MB)
Ethernet:	8x 10G via 2x RTL8264 PHY
LEDs:		2 LEDs, 1 power green, 1 system green
Button:		Reset
USB ports:	None
Bootloader:	Realtek U-Boot - U-Boot 2011.12.(3.6.6.55087) (Nov 13 2022 - 14:37:31)
Fan:            2 fans controlled by STC8G1K08 TSOP-20 microcontroller

Note: The fan appears to operate the same irrespective of the running
firmware. The STC9G1K08 is likely operating independently.

To explore the stock vendor firmware, there are 2 avenues to gain root
access. This is not necessary to install OpenWrt, but is here for
reference.

Root access via serial
----------------------
1. ctrl+t
2. password: switchrtk
3. press 's' for shell

Root access via SSH
-------------------
1. ctrl+t
2. password: switchrtk
3. sys command sh
4. log in with your username+password
5. ctrl+t
6. password: switchrtk
7. press 's' for shell

Credit to https://forum.openwrt.org/t/hasivo-switches/151758/174 for rooting instructions.

Installing OpenWrt
------------------
1. Connect to UART. UART requires soldering an RJ45 connector to the
   console footprint on the board. The header is on the top right of
   this image: https://forum.openwrt.org/uploads/default/original/3X/4/d/4d2ab97fad7e2c5b0a0bdca4de887918c6dcff97.jpeg
2. Set computer IP to 192.168.0.111.
3. Enter bootloader by pressing esc key during boot.
4. Enter password 'Hs2021cfgmg'.
5. Type 'XXXX'.
6. setenv bootcmd 'rtk network on; bootm 0xb4300000'
7. saveenv
8. rtk network on
9. tftpboot 0x84f00000 <openwrt-initramfs>
10. bootm 0x84f00000

Now you can copy over the sysupgrade image and install.

Credit to
https://forum.openwrt.org/t/hasivo-switches/151758/22?u=andrewjlamarche
for u-boot console access instructions.

Signed-off-by: Andrew LaMarche <andrewjlamarche@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/17137
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>