Minor update to BPI-RV2 feature list on web page

Banana Pi BPI-RV2 Risc-V gateway board design with Siflower SF21H8898 chip design | BananaPi Docs says the board has a mikroBUS socket, but the picture does not show a mikroBUS socket. I suspect this might be a violation of the terms of the mikroBUS free license to using the trademark as documented at https://www.mikroe.com/mikrobus.