Defines starting with `r' in iokit/Drivers/network/drvPPCUniN

• RX_INT_LATENCY_uS iokit/Drivers/network/drvPPCUniN/UniNEnetRegisters.h:49
• RX_RING_LENGTH iokit/Drivers/network/drvPPCUniN/UniNEnetRegisters.h:35