componentbase: do not use native buffer by default for libvacodec

add config option --use-libvacodec
when libvacodec is used, set __NATIVE_BUFFER_DEFAULT__ to 0,
otherwise set it to 1.
only if __NATIVE_BUFFER_DEFAULT__ is set to 1, ProcessorEnableNativeBuffers
is called when the port is disabled.

gst-omx do not know the details of VideoRenderBuffer

Signed-off-by: Xu Guangxin <guangxin.xu@intel.com>
Signed-off-by: Zhao Halley <halley.zhao@intel.com>