SD card and audio fixes

Closes #1610 on master branch

This pull is basically the same as pull #1748, but prepared for master branch. I really thing that this should be merged into 2.0.12 as it fixes a couple of important bugs.

Changes:
* sport.log only active if SPORT_FILE_LOG=YES
* audio concurrent access fixes
* added IO mutex
* added Event Trace Buffer
* fixed SD card error

I have tested this on my Taranis for more than 4 hours. Everything that this branch changes works perfect. I think it is safe to merge.

**Warning**: changes to diskio.cpp for 9XRPRO are not tested! I don't have that radio.