staging: wfx: do not use built-in AUTO_ERP feature

staging: wfx: do not use built-in AUTO_ERP feature

Firmware is able to detect detect changes about ERP protection in
beacons and automatically enable/disable ERP protection. However, it not
bring performance improvements and we are more confident in the ERP
handling of mac80211. So, the patch disable this feature.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200415161147.69738-9-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>