wifi: ath12k: encode max Tx power in scan channel list command

Currently, when sending the scan channel list command to the firmware, the
maximum Tx power is not encoded in the reg2 member. This omission causes
the firmware to be unaware of the host's maximum Tx power, leading to
incorrect Tx power derivation at firmware level.

To resolve this issue, encode the maximum Tx power in the scan channel list
command before sending it to firmware.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-QCAHKSWPL_SILICONZ-1
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Fixes: d8899132 ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
Signed-off-by: Sathishkumar Muruganandam <quic_murugana@quicinc.com>
Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
Tested-by: Nicolas Escande <nico.escande@gmail.com>
Link: https://patch.msgid.link/20250107-add_max_reg_pwr_in_scan_ch_list_cmd-v1-1-70d9963a21e4@quicinc.com


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