Mini PCIE HW accelerator for ChaCha20

[Germano Massullo]

After having checked that iperf3 was indeed consuming a lot of a CPU 
core on the Turris Omnia, I modified the Wireguard topology in order to 
have the router to just be the Wireguard gateway among two LAN computers 
( [A] <--wireguard--> [C] <--wireguard--> [B] ), and I have run the 
iperf3 among such computers
iperf3 -c x.x.x.x -P 4 -Z bbr
and the throughput was ~320 Mbit/s. Considering that the router had to 
handle two Wireguard tunnels, one could guess (without any claim of 
accuracy due lack of more accurate tests), that the maximum Wireguard 
throughput that such router can handle is ~2x 320 Mbit/s = ~640 Mbit/s

[A]: Ryzen 5 3600 - kernel 5.14.0-427.18.1.el9_4.x86_64
[B]: Ryzen 7 PRO 6850U -  kernel 6.8.11-300.fc40.x86_64
[C]: Turris Omnia - TurrisOS 7.0.0, kernel 5.15.148