ath11k: fix duplication peer create on same radio

Add the pdev index information in the peer object to validate
the peer creation. Ignore the peer creation request, if the given
MAC address is already present in the peer list with same radio.
If we allow the peer creation in above scenario, FW assert will happen.
Above scenario occurred in two cases, where Multiple AP VAP created in
the same radio.

1. when testing tool sends association request to two AP with same
   MAC address
2. when a station do roaming from one AP VAP to another AP VAP.

Signed-off-by: Karthikeyan Periyasamy <periyasa@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1586343795-21422-1-git-send-email-periyasa@codeaurora.org