x86: add Supermicro SuperServer E302-9D

x86: add Supermicro SuperServer E302-9D

This adds a default network configuration for the
Supermicro SuperServer SYS-E302-9D by adding all
onboard network ports to the default `lan` interface.

The network ports `eth0` till `eth3` use the `igb`
driver, whereas `eth4` till `eth7` use `i40e`.

--- Hardware Highlights ---
CPU: Intel Xeon D-2123IT, 2.20GHz, 4 cores
RAM: Up to 256GB in 4 DIMM Slots
Ports: 4x 1GbE, 2x 10GBase-T, 2x 10G SFP+, 1x IPMI 2.0
Video: 1x VGA
USB: 2x 3.0

Signed-off-by: Til Kaiser <mail@tk154.de>
Link: https://github.com/openwrt/openwrt/pull/17990
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>