Change micropython string

Author: bill88t

py/mpconfig.h

@@ -1869,7 +1869,7 @@ typedef double mp_float_t;
 
 // String used for the banner, and sys.version additional information
 #ifndef MICROPY_BANNER_NAME_AND_VERSION
-#define MICROPY_BANNER_NAME_AND_VERSION "MicroPython " MICROPY_GIT_TAG " on " MICROPY_BUILD_DATE
+#define MICROPY_BANNER_NAME_AND_VERSION "CircuitPython " MICROPY_GIT_TAG " on " MICROPY_BUILD_DATE
 #endif
 
 // String used for the second part of the banner, and sys.implementation._machine