wifi: ath12k: fix timeout while waiting for regulatory update during interface creation

wifi: ath12k: fix timeout while waiting for regulatory update during interface creation

During interface creation, following print is observed on the console -

  Timeout while waiting for regulatory update

This occurs due to commit 906619a00967 ("wifi: ath12k: handle regulatory
hints during mac registration"), which introduced a completion mechanism to
synchronize the regulatory update process. The intent behind this change is
to coordinate the timing between when the firmware sends regulatory data to
the driver and when the driver processes that data.

However, during interface addition, if the 6 GHz band is active, the driver
invokes ath12k_regd_update() to apply the appropriate 6 GHz power mode
regulatory settings. At this point, there is no interaction with the
firmware, so the completion object is not reinitialized. As a result,
wait_for_completion() eventually times out, leading to the observed error
log message.

Hence to fix this, move all complete() on regd_update_completed to
complete_all().

The complete() function signals only once, causing any subsequent waits
without reinitialization to timeout. In this scenario, since waiting is
unnecessary, complete_all() can be used instead, ensuring that subsequent
calls to wait without reinitialization will simply bail out and not
actually wait. This approach is ideal because if the firmware is not
involved, there is no need to wait for the completion event. However, if
the firmware is involved, it is guaranteed that the completion will be
reinitialized, and thus, it would wait.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.5-01651-QCAHKSWPL_SILICONZ-1
Tested-by: Kang Yang <kang.yang@oss.qualcomm.com>
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Fixes: 906619a00967 ("wifi: ath12k: handle regulatory hints during mac registration")
Signed-off-by: Aditya Kumar Singh <aditya.kumar.singh@oss.qualcomm.com>
Link: https://patch.msgid.link/20250626-fix_timeout_during_interface_creation-v1-1-90a7fdc222d4@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>