ath10k: update station counting

Currently station counting functions
(inc_num_stations/dec_num_stations) does not handle
tdls type of stations. Tdls station should be counted
because it consumes peer in firmware. Only not tdls
stations are excluded from this counting.

Signed-off-by: Marek Puzyniak <marek.puzyniak@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>