misc: Reverted version information to "develop"

Change-Id: I6ee1bae48f2dd0d868dfbb428e93deeb9ee93083
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29833
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>

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         = DEVELOP-FOR-V20.1
 
 # 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 = "[DEVELOP-FOR-V20.1]";