libobs: Add sample_rate param to conv_frames_to_time

Prevents from having to query the base audio subsystem for the sample
rate each time the function is called

libobs/media-io/audio-io.h

@@ -182,7 +182,7 @@ static inline uint64_t ns_to_audio_frames(size_t sample_rate,
 {
 	util_uint128_t val;
 	val = util_mul64_64(frames, sample_rate);
-	val = util_div128_32(val, 1000000000ULL);
+	val = util_div128_32(val, 1000000000);
 	return val.low;
 }