wifi: ath11k: rely on mac80211 debugfs handling for vif

In the Linux kernel, the following vulnerability has been resolved: wifi: ath11k: rely on mac80211 debugfs handling for vif mac80211 started to delete debugfs entries in certain cases, causing a ath11k to crash when it tried to delete the entries later. Fix this by relying on mac80211 to delete the entries when appropriate and adding them from the vif_add_debugfs handler.