wifi: ath12k: support 2 channels for single pdev device

wifi: ath12k: support 2 channels for single pdev device

For single pdev device, radio number of a device is forced as 1 in
ath12k_wmi_ext_soc_hal_reg_caps_parse(). This leads to ah->num_radio == 1
and then in ath12k_mac_setup_iface_combinations() we report to
mac/cfg80211 that only 1 channel is supported. In MLO case, it finally
results in failing to bring up the second link as it is in another
channel.

Change num_different_channels to 2 to allow a second link. Since DFS on
multiple channels are not supported yet, remove radar_detect_widths.

For now WCN7850 is the only single pdev device, so others should not be
affected.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00284-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1
Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00209-QCAHKSWPL_SILICONZ-1

Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Link: https://patch.msgid.link/20250409-ath12k-wcn7850-mlo-support-v2-9-3801132ca2c3@quicinc.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>