configs: restore_simpoint_checkpoint should be a boolean

The --restore_simpoint_checkpoint option is a boolean;
however if no default value is supplied, optparse sets the
default value to None

This is not valid for argparse. Argparse recognizes the store_true
action and it is automatically treating the option as a boolean,
hence providing a default=False instead of default=None

Change-Id: I6b09edf6911be71a06001730be1232a1b5c8482c
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/44765
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

configs/common/Options.py

@@ -305,6 +305,7 @@ def addCommonOptions(parser):
     parser.add_option("--take-simpoint-checkpoints", action="store", type="string",
         help="<simpoint file,weight file,interval-length,warmup-length>")
     parser.add_option("--restore-simpoint-checkpoint", action="store_true",
+        default=False,
         help="restore from a simpoint checkpoint taken with " +
              "--take-simpoint-checkpoints")