configs: Fix baremetal platform

With 224da08be7 some MemConfig
functionalities have been moved to the ObjectList module

Change-Id: Iab073b6f8be5a5ea0e49e8974960d7734a5640ba
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23083
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

configs/example/arm/baremetal.py

@@ -57,6 +57,7 @@ m5.util.addToPath('../..')
 
 from common import SysPaths
 from common import MemConfig
+from common import ObjectList
 from common.cores.arm import HPI
 
 import devices
@@ -191,7 +192,7 @@ def main():
     parser.add_argument("--num-cores", type=int, default=1,
                         help="Number of CPU cores")
     parser.add_argument("--mem-type", default="DDR3_1600_8x8",
-                        choices=MemConfig.mem_names(),
+                        choices=ObjectList.mem_list.get_names(),
                         help = "type of memory to use")
     parser.add_argument("--mem-channels", type=int, default=1,
                         help = "number of memory channels")