ath10k: Enable RX batching

This feature allows the FW to batch RX indications,
reducing the rate of host interrupt generation, which
in turn reduces CPU load. Currently, this is enabled
only for the 10.2 firmware.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>