wifi: ath12k: Split scan request for split band device

wifi: ath12k: Split scan request for split band device

When two split-phy devices having supported frequency range in same band
(as mentioned below) are combined into an ath12k HW group, they will be
part of same wiphy and hence the channel list (wiphy->bands[]) will be
common for all of the radios (ar).

1 - 2.4 GHz + 5 GHz Low band
2 - 5 GHz High band + 6 GHz

When a scan is triggered with frequency list containing frequencies of
both 5 GHz low and 5 GHz high, mac80211 generates a single scan request
to driver with both the frequencies. This is because mac80211 splits the
scan request based on band.

ath12k checks the first frequency in the requested scan frequency list and
initiates scan to corresponding radio's(ar) firmware with all the
frequencies. Firmware rejects this scan as some frequencies in the scan
request are not supported, resulting is scan failure.

Fix this by splitting the scan request into multiples scans in driver
based on the supported frequency range of different radios in a band and
schedule scans in parallel to them.
Finally send scan completion/abort notification to mac80211 after all the
radios complete their scheduled scan.

Also, last_scan_link is not needed anymore as ath12k internally schedules
multiple scans, remove the same and use ahvif->links_map to identify
scan links when scan is cancelled.

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

Co-developed-by: Vignesh C <quic_vignc@quicinc.com>
Signed-off-by: Vignesh C <quic_vignc@quicinc.com>
Signed-off-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Reviewed-by: Mahendran P <quic_mahep@quicinc.com>
Link: https://patch.msgid.link/20250507194832.2501668-3-rameshkumar.sundaram@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>