Adding some changes to the FIFOs for 4 streams example

(cherry picked from commit e68ed7092e18035616f6b29783bc2258ad911cb8)

Conflicts:
	module_avb_1722/src/avb_1722_def.h
Tying the number of PTP/MRP ports defines to actual ports
Fixing initialisation error in MVRP attrs

Caused overflow in the single port case
Only set new role on second port if we have one