User needs to follow the outlined
steps for read transaction on serial VBUS :
- Write Vector register with the appropriate vector field ID, address of EDC
Controller register to rd_svbus_address, and set rd_svbus to a 1 to trigger
a read on the serial VBUS.
- Poll Vector register till rd_svbus_done (bit 24) is 1
- Once rd_svbus_done = 1 do a normal read of the reserved_svbus_y register in
the safety aggregator address space, this returns the read value