resources: Updated the README for square

The README for square didn't explicitly mention to clone gem5-resources,
it asks to look for the cpp file in src/gpu which is not present in the
gem5 repository, this is to make sure the user has cloned gem5-resources
instead of just the gem5 repository

Change-Id: Id83f34beac42a7c34ce66bc9649f05a60f985b4d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-resources/+/60709
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
diff --git a/README.md b/README.md
index 7b8096a..7aec42e 100644
--- a/README.md
+++ b/README.md
@@ -327,6 +327,14 @@
 
 To compile:
 
+**Note**: Make sure you are in gem5-resources directory (resources like square are not present in the gem5 repository)
+To clone the gem5-resources repository, run the following command:
+
+```
+git clone https://gem5.googlesource.com/public/gem5-resources
+```
+
+
 ```
 cd src/gpu/square
 docker run --rm -v ${PWD}:${PWD} -w ${PWD} -u $UID:$GID gcr.io/gem5-test/gcn-gpu make gfx8-apu