scripts/gen_compile_commands.py: add acknowledgments

Add acknowledgments for porting and modifying the script. Of course, the
license, author, and copyright notice remain the same as in the original
script.

Signed-off-by: Joao Marcos Costa <jmcosta944@gmail.com>
Tested-by: Joao Paulo Goncalves <joao.goncalves@toradex.com>
diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index 63d036a..1a9c49b 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -4,6 +4,7 @@
 # Copyright (C) Google LLC, 2018
 #
 # Author: Tom Roeder <tmroeder@google.com>
+# Ported and modified for U-Boot by Joao Marcos Costa <jmcosta944@gmail.com>
 #
 """A tool for generating compile_commands.json in U-Boot."""