wifi: ath12k: Power down userPD

wifi: ath12k: Power down userPD

Set the stop bit in SMEM to power down the userPD. Wait for stop-ack IRQ
to indicate power down completion. Release the userPD firmware using its
peripheral ID.

Tested-on: IPQ5332 hw1.0 AHB WLAN.WBE.1.3.1-00130-QCAHKSWPL_SILICONZ-1

Signed-off-by: Sowmiya Sree Elavalagan <quic_ssreeela@quicinc.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Signed-off-by: Raj Kumar Bhagat <quic_rajkbhag@quicinc.com>
Link: https://patch.msgid.link/20250321-ath12k-ahb-v12-12-bb389ed76ae5@quicinc.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>