ath10k: Add peer delete response event

Peer creation in firmware fails if last peer deletion is still
in progress.

The firmware sends a peer delete response event if it advertises
the service WMI_SERVICE_SYNC_DELETE_CMDS. This peer delete response
event is used to synchronize the peer deletion.

Add peer delete response event and wait for the event after
deleting every peer from host driver to synchronize with firmware.

Tested HW: WCN3990
Tested FW: WLAN.HL.2.0-01188-QCAHLSWMTPLZ-1

Signed-off-by: Dundi Raviteja <dundi@codeaurora.org>
Signed-off-by: Rakesh Pillai <pillair@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>