ath11k: Reconfigure hardware rate for WCN6855 after vdev is started

There is an issue that WCN6855 tries to connect to an AP using
a hardware rate of 1Mb/s , even though the AP has announced
expected rates as [24, 36, 48, 54] in Probe Response frame.

The reason is that WCN6855 firmware clears hardware rate info
of management frames when vdev starts and uses 1Mb/s as default.
To solve it, reconfigure the rate after vdev is started.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-01720.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1

Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220112025400.2222-1-quic_bqiang@quicinc.com