tizenaudio-policy: Set use_internal_codec value of combine sink

tizenaudio-policy: Set use_internal_codec value of combine sink

When a stream is finished, routing path should be updated for one
of remaining streams. If one of them is using internal audio codec
with a combine sink, it should also be updated for the stream.

This patch sets the use_internal_codec value of the combine sink to
true when loading the module if needed.

A function to load the combine module is added and applied.

[Version] 13.0.42
[Issue Type] Bug fix / Refactoring

Change-Id: I02950f4df59535039409b9c75c627dc770c66462
Signed-off-by: Sangchul Lee <sc11.lee@samsung.com>