Gitignore update

Added to .gitignore directives to ignore the folders and files created
after the run of a benchmark

.gitignore

@@ -35,3 +35,10 @@
 *.app
 
 # End of https://www.gitignore.io/api/c++
+
+# Files and folders created after the run of the benchmarks
+results/*
+charts/*
+plot/*
+time-and-save.sh
+SmartPower