ath10k: allow user to toggle ani_enable via debugfs

Now that ANI is enabled by default, allow user to disable or enable ANI feature
from debugfs

echo 0|1 > /sys/kernel/debug/ieee80211/phyX/ath10k/ani_enable

Signed-off-by: Ashok Raj Nagarajan <arnagara@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>