misc: Updated release notes and version number

Updated the release notes and version number for the v20.0.0.3
hot-fix.

Change-Id: I3fe8eda1e6859f76a91fbcee595426bd25bfe432
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30956
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>

RELEASE-NOTES.md

@@ -1,3 +1,7 @@
+# Version 20.0.0.3
+
+**[HOTFIX]** When using the ARM ISA, gem5 could crash when a guest tried to call m5ops. This was due to `m5ops_base` being incorrectly declared in `src/arch/arm/ArmSystem.py`. A fix was applied to remove this declaration.
+
 # Version 20.0.0.2
 
 **[HOTFIX]** A patch was applied to fix the RubyPrefetcher with MESI_Three_Level. Prior to this fix a segfault occurred.

src/Doxyfile

@@ -31,7 +31,7 @@ PROJECT_NAME           = gem5
 # This could be handy for archiving the generated documentation or 
 # if some version control system is used.
 
-PROJECT_NUMBER         = v20.0.0.2
+PROJECT_NUMBER         = v20.0.0.3
 
 # The OUTPUT_DIRECTORY tag is used to specify the (relative or absolute) 
 # base path where the generated documentation will be put. 

src/base/version.cc

@@ -26,4 +26,4 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-const char *gem5Version = "20.0.0.2";
+const char *gem5Version = "20.0.0.3";