LPC5500: Only enable TRACECLK if at least 1 core was discovered.
LPC5500: Only enable TRACECLK if at least 1 core was discovered.

mesheven/pyOCD,mesheven/pyOCD,mbedmicro/pyOCD,pyocd/pyOCD,pyocd/pyOCD,flit/pyOCD,mbedmicro/pyOCD,flit/pyOCD,mbedmicro/pyOCD,mesheven/pyOCD