ath10k: enable peer stats by default

IFTYPE_MESH_POINT need to rely on these for accurate path
selection metrics. Other modes will probably also find
them useful. Enabling peer stats has the side effect of
reducing max number of STAs from 128 to 118. There should
be negligible performance impact.

If users really need 128 STAs and don't mind losing out on
peer stats, they can still disable them:

echo 0 > debugfs/ieee80211/phyn/ath10k/peer_stats

Signed-off-by: Thomas Pedersen <twp@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>