ath11k: support TXOP duration based RTS threshold

HE operation IE in beacons is constructed based on userspace params,
which firmware might not be aware of. This causes firmware not to
configure TXOP duration based RTS threshold which could cause mismatch
in behaviour with respect to what is being advertised in beacons. This
patch sends HE operation IE fetched from beacon to firmware using
WMI interface for configuration.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.1.0.1-01228-QCAHKSWPL_SILICONZ-1

Signed-off-by: Pradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201020183111.25458-4-pradeepc@codeaurora.org