Revert the YUV->RGB matrices to the values

Fixes the issue that causes GPUImage to render videos brighter than AVPlayer
The numbers are pulled directly from the diff of this change here: https://github.com/BradLarson/GPUImage/commit/2ad3e9cbbc9a2943f61e1cde1587f09cc180c738
Only changes the numbers, nothing else, tiny change