add comment for LTO enable with HybridCompile

Add check for enabling LTO in Arduino build process.

Author: Jason2866

builder/frameworks/arduino.py

@@ -599,6 +599,7 @@ def has_psram_config():
     if has_unicore_flags():
         build_unflags += " -ustart_app_other_cores"
 
+    # Check for enabling LTO for Arduino HybridCompile part by unflagging -fno-lto
     if '-fno-lto' in build_unflags:
         flag_lto = True