stlport: Force building PIC code

Required for gcc 4.7

Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
stlport: Fix strict aliasing violations

This patch fixes strict aliasing violations.
Forward-ported from Chao Yang <chao.yang@linaro.org>'s
patch for 2.3.5.

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