rtwn: add VHT information to TX rate completion

[adrian]

Summary

• Extend the RTWN_RIDX VHT macros to include ridx -> VHT { MCS, NSS }
• Use it in the RX completion path
• Add VHT information to the TX completion path
• Add the PHY type to the TX completion path so rate control can eventually know the difference between completion of CCK, OFDM, HT and VHT frames.

[fuz]

This also looks reasonable.

sys/dev/rtwn/rtl8812a/r12a_rx.c

115

This compiles due to the macro having parentheses, but made me double-take when I read it.

[bz]

fuz + this information is used nowhere currently. I'll wait along with D48096 until I see this being used for anything.