ipq-wifi: Work around Plasma Cloud PA1200 5GHz crash

ipq-wifi: Work around Plasma Cloud PA1200 5GHz crash

It was noticed [1] that the ath10k firmware crashes on 5GHz since OpenWrt
21.02.0. The problem seems to be triggered by the the nonLinearTxFir field
in the 5GHz BDF. If baseEepHeader.nonLinearTxFir (offset 0xc2) is 1 then
the firmware just crashes when setting up the 5Ghz radio using `ifconfig
wlan1 up`:

  ath10k_ahb a800000.wifi: firmware crashed! (guid 9e36ee82-4d2c-4c63-b20b-609a1eaca30c)
  ath10k_ahb a800000.wifi: qca4019 hw1.0 target 0x01000000 chip_id 0x003b00ff sub 0000:0000
  ath10k_ahb a800000.wifi: kconfig debug 0 debugfs 1 tracing 0 dfs 1 testmode 0
  ath10k_ahb a800000.wifi: firmware ver 10.4-3.6-00140 api 5 features no-p2p,mfp,peer-flow-ctrl,btcoex-param,allows-mesh-bcast,no-ps crc32 ba79b746
  ath10k_ahb a800000.wifi: board_file api 2 bmi_id 0:17 crc32 5f400efc
  ath10k_ahb a800000.wifi: htt-ver 2.2 wmi-op 6 htt-op 4 cal pre-cal-file max-sta 512 raw 0 hwcrypto 1
  ath10k_ahb a800000.wifi: firmware register dump:
  ath10k_ahb a800000.wifi: [00]: 0x0000000B 0x000015B3 0x009C3C27 0x00975B31
  ath10k_ahb a800000.wifi: [04]: 0x009C3C27 0x00060530 0x00000018 0x004176B8
  ath10k_ahb a800000.wifi: [08]: 0x00405A50 0x00412A30 0x00000000 0x00000000
  ath10k_ahb a800000.wifi: [12]: 0x00000009 0x00000000 0x009B9742 0x009B974F
  ath10k_ahb a800000.wifi: [16]: 0x00971238 0x009B9742 0x00000000 0x00000000
  ath10k_ahb a800000.wifi: [20]: 0x409C3C27 0x004053DC 0x00000D2C 0x00405A60
  ath10k_ahb a800000.wifi: [24]: 0x809C3E13 0x0040543C 0x00000000 0xC09C3C27
  ath10k_ahb a800000.wifi: [28]: 0x809B9AC5 0x0040547C 0x00412A30 0x0040549C
  ath10k_ahb a800000.wifi: [32]: 0x809B8ECD 0x0040549C 0x00000001 0x00412A30
  ath10k_ahb a800000.wifi: [36]: 0x809B8FF3 0x004054CC 0x00412838 0x00000014
  ath10k_ahb a800000.wifi: [40]: 0x809BEF98 0x0040551C 0x0041627C 0x00000002
  ath10k_ahb a800000.wifi: [44]: 0x80986D47 0x0040553C 0x0041627C 0x00416A88
  ath10k_ahb a800000.wifi: [48]: 0x809CBB0A 0x0040559C 0x0041ACC0 0x00000000
  ath10k_ahb a800000.wifi: [52]: 0x809864EE 0x0040560C 0x0041ACC0 0x00000001
  ath10k_ahb a800000.wifi: [56]: 0x809CA8A4 0x0040564C 0x0041ACC0 0x00000001
  ath10k_ahb a800000.wifi: Copy Engine register dump:
  ath10k_ahb a800000.wifi: [00]: 0x0004a000  14  14   3   3
  ath10k_ahb a800000.wifi: [01]: 0x0004a400  16  16  22  23
  ath10k_ahb a800000.wifi: [02]: 0x0004a800   3   3   2   3
  ath10k_ahb a800000.wifi: [03]: 0x0004ac00  15  15  15  15
  ath10k_ahb a800000.wifi: [04]: 0x0004b000   4   4  44   4
  ath10k_ahb a800000.wifi: [05]: 0x0004b400   3   3   2   3
  ath10k_ahb a800000.wifi: [06]: 0x0004b800   1   1   1   1
  ath10k_ahb a800000.wifi: [07]: 0x0004bc00   1   1   1   1
  ath10k_ahb a800000.wifi: [08]: 0x0004c000   0   0 127   0
  ath10k_ahb a800000.wifi: [09]: 0x0004c400   0   0   0   0
  ath10k_ahb a800000.wifi: [10]: 0x0004c800   0   0   0   0
  ath10k_ahb a800000.wifi: [11]: 0x0004cc00   0   0   0   0
  ath10k_ahb a800000.wifi: failed to update channel list: -108
  ath10k_ahb a800000.wifi: failed to set pdev regdomain: -108
  ath10k_ahb a800000.wifi: failed to create WMI vdev 0: -108
  ieee80211 phy1: Hardware restart was requested

Since no actual solution is known (besides downgrading the ath10k firmware)
it seems to be better to disable the nonLinearTxFir for now.

[1] https://lore.kernel.org/ath10k/3423718.UToCqzeSYe@ripper/

Signed-off-by: Sven Eckelmann <sven@narfation.org>