Fix overload of SoftVideoDecoderOMXComponent::updatePortDefinitions

An overloaded function should take the same parameters as the function
it is overloading.

Change-Id: I8327fe1b363917515cf76c8f76bdbc05b2c0fbf0
Signed-off-by: Bernhard Rosenkränzer <Bernhard.Rosenkranzer@linaro.org>