iw command only show rssi without each chain's rssi on sdio
iw wlan0 station dump
Station a0:40:a0:93:3e:de (on wlan0)
signal:         -82 dBm
signal avg:     -82 dBm

after this patch, it will show each chain's rssi on sdio
Station a0:40:a0:93:3e:de (on wlan0)
signal:         -82 [-84, -88] dBm
signal avg:     -82 [-84, -87] dBm

For QCA6174 PCIe, the ppdu have the correct rssi of each chain, it
indicate rssi of rx data by ath10k_htt_rx_h_signal. For sdio chip, the
rssi of each chain stored in rx management reported by firmware, the
ath10k_wmi_tlv_op_pull_mgmt_rx_ev which used for tlv wmi will get the
rssi of each chain and stored them in wmi_mgmt_rx_ev_arg, then indicate
them to mac80211. For non-tlv wmi chip, it will not get the rssi of each
chain and not indicate to mac80211, for non-tlv wmi chip, this patch will
not have impact. For tlv wmi chip, if the rssi of chain in mgmt is valid,
it will be indicate to mac80211, tested with QCA6174 PCIe/SDIO, the rssi
of 2 chain in mgmt is valid.

rssi of chains in mgmt of QCA6174 SDIO:
92096.652780: ath10k:ath10k_log_warn: ath10k_sdio mmc1:0001:1 rssi[0]:70
92096.657324: ath10k:ath10k_log_warn: ath10k_sdio mmc1:0001:1 rssi[1]:68
92096.662009: ath10k:ath10k_log_warn: ath10k_sdio mmc1:0001:1 rssi[2]:128
92096.666647: ath10k:ath10k_log_warn: ath10k_sdio mmc1:0001:1 rssi[3]:128

rssi of chains in mgmt of QCA6174 PCIe:
[ 1581.049816] ath10k_pci 0000:02:00.0: mgmt rssi[0]:17
[ 1581.049818] ath10k_pci 0000:02:00.0: mgmt rssi[1]:22
[ 1581.049821] ath10k_pci 0000:02:00.0: mgmt rssi[2]:128
[ 1581.049823] ath10k_pci 0000:02:00.0: mgmt rssi[3]:128

after apply this patch, the iw's rssi of PCIe do not changed, result is
same with before.

iw wlan0 station dump of QCA6174 PCIe:
Station 6c:e8:73:b8:92:dc (on wlan0)
        signal:         -70 [-77, -72] dBm
        signal avg:     -69 [-78, -72] dBm

iw wlan-5000mhz station dump of QCA9984 PCIe
connected with 2 client which has 2 chain:
Station 70:48:0f:1f:1a:b2 (on wlan-5000mhz)
        signal:         -47 [-55, -48, -87, -88] dBm
        signal avg:     -42 [-50, -43, -83, -86] dBm
Station ac:c1:ee:39:e3:83 (on wlan-5000mhz)
        signal:         -43 [-46, -45, -79, -84] dBm
        signal avg:     -43 [-46, -46, -82, -83] dBm

Tested with QCA6174 SDIO with firmware WLAN.RMH.4.4.1-00017-QCARMSWP-1.
Tested with QCA6174 PCIe with firmware WLAN.RM.4.4.1-00110-QCARMSWP-1.
Tested with QCA9984 PCIe with firmware 10.4-3.9.0.2-00040.
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>