Pull Request - Adding new element and fix some errors

Hi,

We have made some changes on your repository. Please check our commits. 

Log : 

-> Add new element based on OMX.TI.VPSSM3.VSWMOSAIC component (Current limitation : 2 fixed entry) because we had face to some troubles with the current omx_videomixer after one run.   

-> Fix noisefilter implementation. Based on TI documentation, we must have 32 bits align sizes. 

-> Fix FreeHandle on omx_core

Feedbacks are welcome. 

Regards