wifi: ath11k: fix VHT MCS assignment

wifi: ath11k: fix VHT MCS assignment

While associating, firmware needs to know peer's receive capability to
calculate its own VHT transmit MCS, currently host sends this information
to firmware via mcs->rx_mcs_set field, this is wrong as firmware actually
takes it from mcs->tx_mcs_set field. Till now there is no failure seen
due to this, most likely because almost all peers are advertising the
same capability for both transmit and receive. Swap the assignment to
fix it.

Besides, rate control mask is meant to limit our own transmit MCS, hence
need to go via mcs->tx_mcs_set field. With the aforementioned swapping
done, change is needed as well to apply it to the peer's receive
capability rather than transmit capability.

Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.41
Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1

Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Signed-off-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Link: https://patch.msgid.link/20251017-ath11k-mcs-assignment-v1-1-da40825c1783@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>