ath10k: move ath10k_mac_tdls_vif*() functions

To be able to use ath10k_mac_tdls_vif_stations_count() in
ath10k_hw_scan() in the following patch, move the functions
earlier in the file.

This commit is pure code move, no functional changes.

Signed-off-by: Anilkumar Kolli <akolli@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>