hostap: use ndo_siocdevprivate

hostap has a combination of iwpriv ioctls that do not work at
all, and two SIOCDEVPRIVATE commands that work natively but
lack a compat conversion handler.

For the moment, move them over to the new ndo_siocdevprivate
interface and return an error for compat mode.

Cc: Jouni Malinen <j@w1.fi>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>