wifi: ath12k: use WMI_VDEV_SET_TPC_POWER_CMDID when EXT_TPC_REG_SUPPORT for 6 GHz

wifi: ath12k: use WMI_VDEV_SET_TPC_POWER_CMDID when EXT_TPC_REG_SUPPORT for 6 GHz

When station is connected to a 6 GHz AP, there are 2 ways to configure the
power limit to firmware. The first way is to send 2 WMI commands
WMI_PDEV_PARAM_TXPOWER_LIMIT2G/WMI_PDEV_PARAM_TXPOWER_LIMIT5G to firmware,
the second way is to send WMI_VDEV_SET_TPC_POWER_CMDID to firmware which
includes more parameters for power control.

When firmware advertises WMI_TLV_SERVICE_EXT_TPC_REG_SUPPORT, it supports
WMI_VDEV_SET_TPC_POWER_CMDID, ath12k uses it to send more parameters to
firmware. As chanctx is needed to extract necessary info for this command,
save it beforehand in ath12k_mac_op_assign_vif_chanctx().

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-v1-15-c869c86cad60@quicinc.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>