Adding support for new rev of audio slice

Conflicts:
	app_daisy_chain/Makefile
	app_daisy_chain/xmos_board_info/SLICEKIT-L2/avb_app_board_config.h
	app_simple_avb_demo/src/main.xc
Tidying up some MRP debug
Removing const qual required to work around bug 14445
Refactoring C calls from XC to use extern "C"
Fixing PLL I2C address for daisy chain
Adding identify command and 1722.1 callback interface
Removing control prints
Removing another control print
Forgot to commit callbacks header
Moving I2C setup as a distributable task
Removing interface loop that caused lock up on link down
Removing interface macro, now present in xccompat.h
PTP now throws aways outlier sync measurements
Many memory optimisations, mostly array copies
First implementation of firmware upgrade via 1722.1
Removes warnings about signess of parameters
Added bandwidth calculations for setting Qav shaper per port
Forgot to not add extra byte when the stream originates here
Adding argument to set Qav rate per port
Propagate attributes not only if the MAD_join/request is new