wifi: ath12k: advertise NL80211_FEATURE_TX_POWER_INSERTION support

wifi: ath12k: advertise NL80211_FEATURE_TX_POWER_INSERTION support

Now that driver is capable of inserting Tx power, advertise the support
for the same to upper layers.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1

Signed-off-by: Aditya Kumar Singh <aditya.kumar.singh@oss.qualcomm.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Link: https://patch.msgid.link/20250630-support-for-tx-power-insertion-v1-2-77f45484d5bb@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>