all: Format code to add space after C++-style comment start.

Note: the uncrustify configuration is explicitly set to 'add' instead of
'force' in order not to alter the comments which use extra spaces after //
as a means of indenting text for clarity.

ports/esp8266/main.c

@@ -158,7 +158,7 @@ void MP_FASTCODE(nlr_jump_fail)(void *val) {
     }
 }
 
-//void __assert(const char *file, int line, const char *func, const char *expr) {
+// void __assert(const char *file, int line, const char *func, const char *expr) {
 void __assert(const char *file, int line, const char *expr) {
     printf("Assertion '%s' failed, at file %s:%d\n", expr, file, line);
     for (;;) {