SEGGER_RTT_MEMCPY_USE_BYTELOOP macro

RTT memcpy configuration memcpy() is good for large amounts of data, but the overhead is big for small amounts, which are usually stored via RTT. With SEGGER_RTT_MEMCPY_USE_BYTELOOP a simple byte loop can be used instead. SEGGER_RTT_MEMCPY() can be used to replace standard memcpy() in RTT functions. This is may be required with memory access restrictions, such as on Cortex-A devices with MMU.