wext: Re-add support for SIGNAL_POLL and DRIVER

Both of these are still used by JB, and wext wifi drivers have some
weird behaviors without it (like a reported poor connection 100% of
the time)

Change-Id: I15339dbea4e15831465e2bb52b11675cb20dc34c
hostapd: Fix aliasing violation

Change-Id: I1661f1e50959165542aed00374467715dc26d847
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>