wifi: ath12k: handle symlink cleanup for per pdev debugfs dentry

wifi: ath12k: handle symlink cleanup for per pdev debugfs dentry

Whenever per pdev debugfs directory is created, a symlink to it is also
placed in ieee80211/phy* directory. During clean up of per pdev debugfs,
this symlink also needs to be cleaned up.

Add changes to clean up the symlink whenever the per pdev debugfs is
removed.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0.1-00029-QCAHKSWPL_SILICONZ-1

Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://msgid.link/20240529043043.2488031-4-quic_adisi@quicinc.com