wifi: ath12k: store reg info for later use

Currently we only build regdomain when channel list event is received.
That event is received when driver boots or when a new country code is
sent to firmware. At either time we may have no information about
interface mode or AP's power type, consequently WMI_REG_INDOOR_AP is
selected. In upcoming patches we will rebuild regdomain once those
information is available. For that purpose reg info has to be
stored/refreshed each time a new channel list event is received.

The stored reg info would be freed in ath12k_reg_free() when it is not
needed.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Link: https://patch.msgid.link/20250418-ath12k-6g-lp-vlp-v1-6-c869c86cad60@quicinc.com


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