rt2800: enable MFP support unconditionally

This gives us WPA3 support out of the box without having to manually disable
hardware crypto. The driver will fall back to software crypto if the connection
requires management frame protection.

Suggested-by: Stanislaw Gruszka <stf_xl@wp.pl>
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
Acked-by: Stanislaw Gruszka <stf_xl@wp.pl>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200525134906.1672-1-rsalvaterra@gmail.com