ath10k: enable periodic peer stats update

ath10k: enable periodic peer stats update

Register for 500ms as periodic peer stats update period,
and parameters like rx_duration that needs to be tracked
in host can be achieved by this provision, also periodic
stats update is the future of fw_stats and shall be extended
for pdev / vdev stats irrespecitive PEER_STATS service is enabled
or not

Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qti.qualcomm.com>
[kvalo@qca.qualcomm.com: fix a checkpatch warning]
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>