staging: wfx: remove handling of "early_data"

It seems that purpose of "early_data" was to prevent sending data to
mac80211 before station was completely associated. It is a useless
precaution.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200115135338.14374-46-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>