libwifi: rename mtk.c to mac80211.c
Today mtk.c implement mac80211.c module. This works perfectly also with other HW, vendors like QCA - ath9k/ath10k and probably in the future also with ath11k.
mac80211.c - should be common implementation for all mac80211 compatile drivers.
Signed-off-by: Janusz Dziedzic janusz.dziedzic@iopsys.eu