all: format code according to Go 1.19 rules

Go 1.19 started reformatting code in a way that makes it more obvious
how it will be rendered on pkg.go.dev. It gets it almost right, but not
entirely. Therefore, I had to modify some of the comments so that they
are formatted correctly.

src/runtime/runtime_stm32_timers.go

@@ -62,6 +62,7 @@ func nanosecondsToTicks(ns int64) timeUnit {
 }
 
 // number of ticks since start.
+//
 //go:linkname ticks runtime.ticks
 func ticks() timeUnit {
 	// For some ways of capturing the time atomically, see this thread: