feat(log): improve lv_log and add log the result from lv_demo_benchmark (#3084)

* feat(log): improve log

* Update log.md

* Update log.md

* fix: fix formatting issue

* fix: fix formatting again...

* fix: remove blanks

docs/porting/log.md

@@ -43,4 +43,11 @@ lv_log_register_print_cb(my_log_cb);
 
 ## Add logs
 
-You can also use the log module via the `LV_LOG_TRACE/INFO/WARN/ERROR/USER(text)` functions.
+You can also use the log module via the `LV_LOG_TRACE/INFO/WARN/ERROR/USER(text)` or `LV_LOG(text)` functions. Here:
+
+-  `LV_LOG_TRACE/INFO/WARN/ERROR/USER(text)` append following information to your `text`
+  - Log Level
+  - \_\_FILE\_\_
+  - \_\_LINE\_\_
+  - \_\_func\_\_
+- `LV_LOG(text)` is similar to `LV_LOG_USER` but has no extra information attached.