buildroot

wvstreams: disable warnings

During the compilation of wvstreams, a number of strict aliasing
related warnings are shown, making the build quite noisy. Turn
warnings off using the --disable-warnings option.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>