resources: Updates dist.gem5.org/images URLs

http: //dist.gem5.org/images has been moved to
http: //dist.gem5.org/dist/v20/images. This patch updates the URLs.
Change-Id: I02ab4608a470f003284fb66f6f8185d9fc022548
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-resources/+/35119
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/README.md b/README.md
index 90760ed..0beb035 100755
--- a/README.md
+++ b/README.md
@@ -388,7 +388,7 @@
 `src/gapbs/README.md` contains build and usage instructions.
 
 The pre-built GAPBS disk image can be found here:
-<http://dist.gem5.org/images/x86/ubuntu-18-04/gapbs>.
+<http://dist.gem5.org/dist/v20/images/x86/ubuntu-18-04/gapbs>.
 
 # Resource: PARSEC Benchmark Suite
 
@@ -400,7 +400,7 @@
 `src/parsec/README.md` for build and execution information.
 
 A pre-built parsec benchmark image, for X86, can be found here:
-<http://dist.gem5.org/images/x86/ubuntu-18-04/parsec>.
+<http://dist.gem5.org/dist/v20/images/x86/ubuntu-18-04/parsec>.
 
 # Resource: NAS Parallel Benchmarks (NPB) Tests
 
@@ -409,7 +409,7 @@
 five Lunux Kernels and three pseudo-applications. gem5 resources provides a
 disk image, and scripts allowing for the NPB image to be run within gem5 X86
 simulations. A pre-built npb disk image can be downloaded here:
-<http://dist.gem5.org/images/x86/ubuntu-18-04/npb>.
+<http://dist.gem5.org/dist/v20/images/x86/ubuntu-18-04/npb>.
 
 The npb resources can be found in `src/npb`. It consists of:
 - npb disk image resources
diff --git a/src/boot-exit/README.md b/src/boot-exit/README.md
index 1dd9bb7..210f962 100755
--- a/src/boot-exit/README.md
+++ b/src/boot-exit/README.md
@@ -77,7 +77,7 @@
 ```
 
 Once this process succeeds, the disk image can be found on `boot-exit/boot-exit-image/boot-exit`.
-A disk image already created following the above instructions can be found [here](http://dist.gem5.org/images/x86/ubuntu-18-04/boot-exit) (**warning:** file size is 1.9 GB).
+A disk image already created following the above instructions can be found [here](http://dist.gem5.org/dist/v20/images/x86/ubuntu-18-04/boot-exit) (**warning:** file size is 1.9 GB).
 
 
 ## gem5 Run Scripts
diff --git a/src/gapbs/README.md b/src/gapbs/README.md
index 70c228b..92441e8 100644
--- a/src/gapbs/README.md
+++ b/src/gapbs/README.md
@@ -1,7 +1,7 @@
 # GAP Benchmark Suite (GAPBS) tests
 This document provides instructions to create a GAP Benchmarks Suite (GAPBS) disk image, which, along with provided configuration scripts, may be used to run GAPBS within gem5 simulations.
 
-A pre-build disk image, for X86, can be found here: <http://dist.gem5.org/images/x86/ubuntu-18-04/gapbs>.
+A pre-build disk image, for X86, can be found here: <http://dist.gem5.org/dist/v20/images/x86/ubuntu-18-04/gapbs>.
 
 ## Building the Disk Image
 Assuming that you are in the `src/gapbs/` directory, first create `m5` (which is needed to create the disk image):
diff --git a/src/npb/README.md b/src/npb/README.md
index edf2493..087f5b2 100755
--- a/src/npb/README.md
+++ b/src/npb/README.md
@@ -73,7 +73,7 @@
 ```
 
 Once this process succeeds, the created disk image can be found on `npb/npb-image/npb`.
-A disk image already created following the above instructions can be found [here](http://dist.gem5.org/images/x86/ubuntu-18-04/npb) (**warning:** file size is 2.3 GB).
+A disk image already created following the above instructions can be found [here](http://dist.gem5.org/dist/v20/images/x86/ubuntu-18-04/npb) (**warning:** file size is 2.3 GB).
 
 For more information on the npb disk creation process using packer refer [here](https://gem5art.readthedocs.io/en/latest/main-doc/disks.html#) and [here](https://gem5art.readthedocs.io/en/latest/tutorials/npb-tutorial.html).