ath10k: change the fw stats access mask

This fix the regerssion introduced after "ath10k_wmi_requests_stats()
call to use more stat bits", both the 10.2.X FW and community FW 10.1.X
will return time out when access the fw_stats with the STAT_VDEV and
STAT_PDEV. Add the condition to use different fw_stats mask for different
FW versions.

Fixes: 7777d8c7ef6f ("ath10k: implement fw stats for wmi-tlv")
Signed-off-by: Yanbo Li <yanbol@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>