wifi: ath12k: Rename hw_link_id to radio_idx in ath12k_ah_to_ar()

wifi: ath12k: Rename hw_link_id to radio_idx in ath12k_ah_to_ar()

ath12k_ah_to_ar() is returning radio from the given hardware based on the
radio index passed. But, the variable that radio index is received at is
wrongly named 'hw_link_id', which points to the hardware link index that
comes from the firmware. This affects readability.

Resolve this by renaming 'hw_link_id' to 'radio_idx'.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1

Signed-off-by: Roopni Devanathan <roopni.devanathan@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Link: https://patch.msgid.link/20260331045834.1181924-1-roopni.devanathan@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>