wifi: ath12k: parse and save sbs_lower_band_end_freq from WMI_SERVICE_READY_EXT2_EVENTID event

Firmware sends the boundary between lower and higher bands in
ath12k_wmi_dbs_or_sbs_cap_params structure embedded in
WMI_SERVICE_READY_EXT2_EVENTID event. The boundary is needed when
updating frequency range in the following patch. So parse and save
it for later use. Note ath12k_wmi_dbs_or_sbs_cap_params is placed
after some other structures, so placeholders for them are added
as well.

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.1.4.1-00199-QCAHKSWPL_SILICONZ-1

Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Link: https://patch.msgid.link/20250522-ath12k-sbs-dbs-v1-2-54a29e7a3a88@quicinc.com


Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>