build/core: Don't use -fno-strict-aliasing

Don't use -fno-strict-aliasing: It's no longer needed.

Change-Id: I7b6e9524197dc152b57a8d1900dd6d7f9fe3452d
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>