wifi: rtw89: debug: bb_info entry including TX rate count for WiFi 7 chips

wifi: rtw89: debug: bb_info entry including TX rate count for WiFi 7 chips

Enhance TX performance visibility for WiFi 7 chips by introducing TX
rate count tracking. This is critical for debugging and validation.
Additionally, introduce a new debugfs bb_info to enable and provide
baseband status.

Usage of bb_info debugfs:
  $ echo enable 1 > bb_info  // Start logging BB statistics information
  $ echo mac_id 0 > bb_info  // Specify mac_id for TX rate count tracking

The output of bb_info:

  TP TX: 0 [0] Mbps, RX: 0 [0] Mbps
  Avg packet length: TX=118, RX=136
  TF: 0
  TX count [0]:
     Legacy: [0, 0, 0, 0]
       OFDM: [0, 0, 0, 0, 0, 0, 0, 0]
    MCS 1SS: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
    MCS 2SS: [183, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

  [PHY 0]
  == RSSI/RX Rate
  Beacon: 19 (-41 dBm)
  RX count:
     Legacy: [0, 0, 0, 0]
       OFDM: [0, 0, 0, 0, 0, 0, 0, 0]
       HT 0: [0, 0, 0, 0, 0, 0, 0, 0]
       HT 1: [0, 0, 0, 0, 0, 0, 0, 0]
    VHT 1SS: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0][0, 0]
    VHT 2SS: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0][0, 0]
     HE 1SS: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
     HE 2SS: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
    EHT 1SS: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0][0, 0]
    EHT 2SS: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 185]

  TX rate [0, 2]: EHT 2SS MCS-0 GI:0.8 FB_G BW:160 (hw_rate=0x420) ==> agg_wait=-1 (1)
  RX rate [0, 2]: EHT 2SS MCS-13 GI:0.8 BW:160 (hw_rate=0x42d)
  RSSI: -43 dBm (raw=134, prev=135) [-43, -44]
  EVM: [38.75, (41.50, 43.00)]    SNR: 39

Signed-off-by: Kuan-Chung Chen <damon.chen@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20260429132625.1659182-4-pkshih@realtek.com