Changes made to the .hal definition:
- introduce Effect ID returned by the IEffectsFactory that
needs to be passed to IStream.{add|remove}Effect; otherwise
it's impossible to retrieve the underlying HAL effect handle;
- change "bus address" in DeviceAddress to "string" type;
- fix signature of some methods w.r.t. returning Result;
- remove unused "struct AudioPatch".
Bug: 30222631
Test: make
Change-Id: Icb51729ef57bb2a5b0b78609735e7481bc04f95c
