wcn36xx: Add wcn36xx_smd_set_sta_default_vht_params()

This commit adds support for setting default VHT parameters, which are
exposed by the extended version 1 STA parameter type.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200910150552.2178882-3-bryan.odonoghue@linaro.org