ath10k: report tx rate using ieee80211_tx_rate_update()

ath10k: report tx rate using ieee80211_tx_rate_update()

Mesh path metric needs tx rate information from ieee80211_tx_status()
call but in ath10k there is no mechanism to report tx rate information
via ieee80211_tx_status(), the tx rate is only accessible via
sta_statiscs() op.

Per peer tx stats has tx rate info available, Tx rate is available
to ath10k driver after every 4 PPDU sent in the air. For each PPDU,
ath10k driver updates rate informattion to mac80211 using
ieee80211_tx_rate_update().

Per peer txrate information is updated through per peer statistics
and is available for QCA9888/QCA9984/QCA4019/QCA998X only

Tested on QCA9984 with firmware-5.bin_10.4-3.5.3-00053
Tested on QCA998X with firmware-5.bin_10.2.4-1.0-00036

Signed-off-by: Anilkumar Kolli <akolli@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>