Adding OpenWrt support for ws-ap3825i

@hurricos
hi, I am testing my AP and need to see how to speed port up:100mb, 1000mb or 10mb
on tp-link c6 with switch, i write comand:

Tp-Link-C6:~# swconfig list
Found: switch0 - mdio.0


Tp-Link-C6:~# swconfig dev switch0 show | grep port:4
        link: port:4 link:up speed:1000baseT full-duplex txflow rxflow auto

but on 3825i does not switch

root@AP3825i:~# swconfig list
root@AP3825i:~#

how see port speed on 3825i board or how see this with additional commands?

i test iperf3 serwer on two ports and see port status
i use two comands:

root@AP3825i:~#iperf3 -s -D
root@AP3825i:~#iperf3 -s -p 5001 -D
local iperf3 test
root@AP3825i:~# iperf3 -c x.x.x.x
Connecting to host x.x.x.x, port 5201
[  5] local x.x.x.x port 37144 connected to x.x.x.x port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   145 MBytes  1.21 Gbits/sec    0   1.94 MBytes
[  5]   1.00-2.00   sec   142 MBytes  1.20 Gbits/sec    0   1.94 MBytes
[  5]   2.00-3.01   sec   144 MBytes  1.20 Gbits/sec    0   1.94 MBytes
[  5]   3.01-4.01   sec   142 MBytes  1.19 Gbits/sec    0   1.94 MBytes
[  5]   4.01-5.01   sec   142 MBytes  1.20 Gbits/sec    0   1.94 MBytes
[  5]   5.01-6.00   sec   142 MBytes  1.20 Gbits/sec    0   1.94 MBytes
[  5]   6.00-7.00   sec   142 MBytes  1.20 Gbits/sec    0   1.94 MBytes
[  5]   7.00-8.01   sec   144 MBytes  1.20 Gbits/sec    0   1.94 MBytes
[  5]   8.01-9.00   sec   142 MBytes  1.20 Gbits/sec    0   1.94 MBytes
[  5]   9.00-10.00  sec   142 MBytes  1.20 Gbits/sec    0   1.94 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  1.40 GBytes  1.20 Gbits/sec    0             sender
[  5]   0.00-10.00  sec  1.40 GBytes  1.20 Gbits/sec                  receiver