resources: Added bin dir to insttest .gitignore

Change-Id: Ia1f0ec90e6824ebe658caefe22024e12776f483f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-resources/+/29301
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: Jason Lowe-Power <power.jg@gmail.com>
diff --git a/src/insttest/.gitignore b/src/insttest/.gitignore
new file mode 100644
index 0000000..5e56e04
--- /dev/null
+++ b/src/insttest/.gitignore
@@ -0,0 +1 @@
+/bin